Vehicle acceleration suppression device and vehicle acceleration suppression method

ABSTRACT

A total certainty factor indicating a total degree of certainty of the parking frame certainty degree and the parking frame entering certainty degree is calculated based on a parking frame certainty degree indicating the degree of certainty that a parking frame is present in a travel direction of a vehicle, and a parking frame entering certainty degree indicating the degree of certainty that the vehicle enters the parking frame. When the total certainty factor is low, acceleration of the vehicle controlled according to an operation amount of an accelerator pedal for instructing a driving force by operation of a driver is suppressed with a low suppression degree, as compared with a case where the total certainty factor is high. Further, the acceleration of the vehicle is suppressed at a low suppression degree according to the travel direction of the vehicle.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromthe prior Japanese Patent Application No. 2012-259206 (filed on Nov. 27,2012), the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to a technology that suppressesacceleration of a vehicle for drive assist at the time of parking thevehicle.

BACKGROUND

As a technology that controls the speed of a vehicle or the like, forexample, there is a safety device disclosed in JP 2003-137001 A.

In the safety device disclosed in JP 2003-137001 A, it is detected thata current position of a vehicle (automobile) is a position that isdeviated from a road (public road or the like) based on map data of anavigation device and information indicating the current position of thevehicle. In addition, when an accelerator operation is in a directionwhere the travel speed of the vehicle increases and it is determinedthat a travel speed of the vehicle is greater than a predeterminedvalue, a throttle is controlled in a deceleration direction regardlessof the accelerator operation from a driver.

Since an object of the technology disclosed in JP 2003-137001 A is toprevent a driver's unintended vehicle acceleration even though anoperational error of an accelerator occurs, the determination of whetheror not the operation of the accelerator is the operational errormatters. Further, in the technology disclosed in JP 2003-137001 A, acondition where the vehicle is disposed at the position deviated fromthe road, and a condition where the accelerator operation is performedin a state where it is detected that the travel speed is equal to orgreater than the predetermined value are used as conditions where it isdetermined that there is a possibility that the operational error of theaccelerator occurs.

However, in the above-described determination conditions, if the vehicleenters a parking lot from the road, the control of the throttle in thedeceleration direction is operated by the vehicle speed. Thus, in theparking lot, operability in traveling or the like until the vehiclemoves to the vicinity of a parking space deteriorates.

SUMMARY

In order to solve the above problem, an object of the present disclosureis to provide a vehicle acceleration suppression device and a vehicleacceleration suppression method capable of suppressing deterioration ofoperability in parking the vehicle and suppressing acceleration due toan operational error of an accelerator.

Solution to Problem

In order to solve the above problem, according to an aspect of thedisclosure, a parking frame entering certainty degree indicating thedegree of certainty that a vehicle enters a parking frame is calculatedbased on a peripheral environment and a travel state of the vehicle.Further, according to the detected travel direction, acceleration of thevehicle is suppressed at a low suppression degree.

According to the aspect of the disclosure, in a state where the parkingframe entering certainty degree is low, it is possible to decrease thesuppression degree of the acceleration to reduce deterioration ofoperability, and in a state where the parking frame entering certaintydegree is high, it is possible to increase the suppression degree of theacceleration to increase an acceleration suppression effect of thevehicle.

Thus, it is possible to suppress deterioration of operability in parkingthe vehicle, and to suppress acceleration due to an operational error ofan accelerator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conceptual diagram illustrating a configuration of a vehiclethat includes a vehicle acceleration suppression device in a firstembodiment of the disclosure;

FIG. 2 is a block diagram illustrating a schematic configuration of thevehicle acceleration suppression device in the first embodiment of thedisclosure;

FIG. 3 is a block diagram illustrating a configuration of anacceleration suppression control content calculation unit;

FIG. 4A to FIG. 4P are diagrams illustrating a pattern of a parkingframe which is a calculation object of a parking frame certainty degreein a parking frame certainty degree calculation unit;

FIG. 5 is a flowchart illustrating a process of determining whether ornot an acceleration suppression operation condition is established by anacceleration suppression operation condition determination unit;

FIG. 6A to FIG. 6C are diagrams schematically illustrating a parkingframe line recognition method due to edge detection;

FIG. 7 is a diagram illustrating a vehicle, a parking frame, and adistance between the vehicle and the parking frame;

FIG. 8 is a flowchart illustrating a process of calculating a parkingframe certainty degree by a parking frame certainty degree calculationunit;

FIG. 9A to FIG. 9D are diagrams illustrating content of a processperformed by a parking frame certainty degree calculation unit;

FIG. 10 is a diagram illustrating content of a process performed by aparking frame certainty degree calculation unit;

FIG. 11 is a flowchart illustrating a process of calculating a parkingframe entering certainty degree by a parking frame entering certaintydegree calculation unit;

FIG. 12 is a diagram illustrating content of a process of detecting adeviation amount between a rear-wheel expected locus and a parking frameof the vehicle;

FIG. 13 is a diagram illustrating a total certainty degree calculationmap;

FIG. 14 is a diagram illustrating an acceleration suppression conditioncalculation map;

FIG. 15 is a flowchart illustrating a process performed by anacceleration suppression instruction value calculation unit;

FIG. 16 is a flowchart illustrating a process performed by a targetthrottle valve opening degree calculation unit;

FIG. 17 is a diagram illustrating a modification example of the firstembodiment of the disclosure;

FIG. 18 is a diagram illustrating a modification example of the firstembodiment of the disclosure;

FIG. 19 is diagram illustrating a modification example of the firstembodiment of the disclosure;

FIG. 20 is a diagram illustrating a modification example of the firstembodiment of the disclosure;

FIG. 21 is diagram illustrating a total certainty degree calculation mapused in a second embodiment of the disclosure;

FIG. 22 is a diagram illustrating an acceleration suppression conditioncalculation map for retreating;

FIG. 23 is a diagram illustrating a modification example of the secondembodiment of the disclosure;

FIG. 24 is a diagram illustrating a total certainty degree calculationmap used in a third embodiment of the disclosure;

FIG. 25 is a diagram illustrating a modification example of the thirdembodiment of the disclosure;

FIG. 26 is a diagram illustrating a modification example of the thirdembodiment of the disclosure; and

FIG. 27 is a diagram illustrating a map used in a process performed byan acceleration suppression control content calculation unit in a fourthembodiment of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the disclosure will now be described with reference tothe drawings.

First Embodiment

Hereinafter, a first embodiment of the disclosure (hereinafter, referredto as the present embodiment) will be described with reference to theaccompanying drawings.

(Configuration)

First, a configuration of a vehicle that includes a vehicle accelerationsuppression device in the present embodiment will be described withreference to FIG. 1. FIG. 1 is a diagram illustrating the configurationof the vehicle that includes the vehicle acceleration suppression devicein the present embodiment.

As illustrated in FIG. 1, a vehicle V includes vehicle wheels W (rightfront wheel WFR, left front wheel WFL, right rear wheel WRR, and leftrear wheel WRL), a brake gear 2, a fluid pressure circuit 4, and a brakecontroller 6. In addition, the vehicle V includes an engine 8 and anengine controller 12.

The brake gear 2 is formed using a wheel cylinder, for example, and isindividually provided to each vehicle wheel W. The brake gear 2 is notlimited to a device that gives a braking force by fluid pressure, andmay be formed using an electric brake gear or the like.

The fluid pressure circuit 4 is a circuit that includes a pipelineconnected to each brake gear 2. The brake controller 6 is configured tocontrol a braking force generated by each brake gear 2 to a value in abraking force instruction value, based on the braking force instructionvalue received from a travel controller 10 which is a higher controller,through the fluid pressure circuit 4. Namely, the brake controller 6forms a deceleration control device. Description relating to the travelcontroller 10 will be made later. Accordingly, the brake gear 2, thefluid pressure circuit 4, and the brake controller 6 form a brake systemthat generates a braking force.

The engine 8 forms a drive source of the vehicle V. The enginecontroller 12 is configured to control torque (driving force) generatedby the engine 8 based on a target throttle valve opening degree signal(acceleration instruction value) received from the travel controller 10.Namely, the engine controller 12 forms an acceleration control device.The target throttle valve opening degree signal will be described later.Accordingly, the engine 8 and the engine controller 12 form a drivesystem which generates the driving force.

The drive source of the vehicle V is not limited to the engine 8, andmay be formed using an electric motor. Further, the drive source of thevehicle V may be formed by a combination of the engine 8 and theelectric motor.

Next, a schematic configuration of the vehicle acceleration suppressiondevice 1 will be described with reference to FIG. 2, while referring toFIG. 1. FIG. 2 is a block diagram illustrating a schematic configurationof the vehicle acceleration suppression device 1 in the presentembodiment.

The vehicle acceleration suppression device 1 includes a peripheralenvironment recognition sensor 14, a vehicle wheel speed sensor 16, asteering angle sensor 18, a shift position sensor 20, a brake operationdetection sensor 22, and an accelerator operation detection sensor 24,as illustrated in FIG. 1 and FIG. 2. In addition, the vehicleacceleration suppression device 1 includes a navigation unit 26, and thetravel controller 10.

The peripheral environment recognition sensor 14 captures a peripheralimage of the vehicle V, and generates, based on each captured image, aninformation signal including an individual image corresponding to pluralimaging directions (also referred to as an “individual image signal” inthe following description). Further, the generated individual imagesignal is output to the travel controller 10.

In the present embodiment, as an example, a case where the peripheralenvironment recognition sensor 14 is formed using a front camera 14F, aright side camera 14SR, a left side camera 14SL, and a rear camera 14Rwill be described. Here, the front camera 14F is a camera that images afront side of the vehicle V in a vehicle longitudinal direction, and theright side camera 14SR is a camera that images a right lateral side ofthe vehicle V. Further, the left side camera 14SL is a camera thatimages a left lateral side of the vehicle V, and the rear camera 14R isa camera that images a rear side of the vehicle longitudinal directionof the vehicle V. The vehicle wheel speed sensor 16 is formed using apulse generator such as a rotary encoder that measures a wheel speedpulse, for example.

Further, the vehicle wheel speed sensor 16 detects a rotational speed ofeach vehicle wheel W, and outputs an information signal including thedetected rotational speed (also referred to as a “wheel speed signal” inthe following description) to the travel controller 10.

The steering angle sensor 18 is provided in a steering column (notillustrated) that rotatably supports a steering wheel 28, for example.Further, the steering angle sensor 18 detects a current steering anglewhich is a current rotation angle (steering operation amount) of thesteering wheel 28 which is a steering operator. In addition, thesteering angle sensor 18 outputs an information signal including thedetected current steering angle (also referred to as a “current steeringangle signal” in the following description) to the travel controller 10.An information signal including a turning angle of the steering wheelmay be detected as the information indicating the steering angle.

The steering operator is not limited to the steering wheel 28 rotated bya driver, and may be a lever through which the driver performs aninclination operation by a hand, for example. In this case, aninclination angle of the lever with respect to a neutral position isoutput as an information signal corresponding to the current steeringangle signal.

The shift position sensor 20 detects a current position of a member thatchanges a shift position (for example, “P”, “D”, “R” or the like) of thevehicle V, such as a shift knob or a shift lever. Further, the shiftposition sensor 20 outputs an information signal including the detectedcurrent position (also referred to as a “shift position signal” in thefollowing description) to the travel controller 10.

The brake operation detection sensor 22 detects an opening degree withrespect to a brake pedal 30 which is a braking force instructionoperator. Further, the brake operation detection sensor 22 outputs aninformation signal including the detected opening degree of the brakepedal 30 (also referred to as a “brake opening degree signal” in thefollowing description) to the travel controller 10.

Here, the braking force instruction operator may be operated by thedriver of the vehicle V, and has a configuration in which the brakingforce of the vehicle V is instructed by change in the opening degree.The braking force instruction operator is not limited to the brake pedal30 that is stepped by a foot of the driver, and may be a lever operatedby a hand of the driver, for example.

The accelerator operation detection sensor 24 is configured to detect anopening degree with respect to an accelerator pedal 32 which is adriving force instruction element. Further, the accelerator operationdetection sensor 24 outputs an information signal including the detectedopening degree of the accelerator pedal 32 (also referred to as an“accelerator pedal opening degree signal” in the following description)to the travel controller 10.

Here, the driving force instruction element may be operated by thedriver of the vehicle V, and has a configuration in which the drivingforce of the vehicle V is instructed by change in the opening degree.The driving force instruction element is not limited to the acceleratorpedal 32 that is stepped by a foot of the driver, and may be a leveroperated by a hand of the driver, for example.

The navigation unit 26 is a device that includes a global positioningsystem (GPS) receiver, a map database, and an information presentationunit having a display monitor or the like, and performs route finding,route guidance or the like.

The navigation unit 26 is capable of obtaining road information such asthe type or width of a road on which the vehicle V is traveling based ona current position of the vehicle V acquired using the GPS receiver androad information stored in the map database.

Further, the navigation unit 26 is configured to output an informationsignal including the current position of the vehicle V acquired usingthe GPS receiver (also referred to as a “vehicle position signal” in thefollowing description) to the travel controller 10. In addition, thenavigation unit 26 is configured to output an information including thetype, width or the like of the road on which the vehicle V is traveling(also referred to as a “traveling road information signal” in thefollowing description) to the travel controller 10.

An information presentation unit is configured to output an alarm orother presentations in a control signal from the travel controller 10using sound or images. Further, the information presentation unitincludes a speaker that performs information provision to the driverusing a buzzer or sound, and a display unit that performs informationprovision by display of images or texts, for example. In addition, thedisplay unit may use a display monitor of the navigation unit 26, forexample.

The travel controller 10 is an electronic control unit configured with acentral processing unit (CPU) and CPU peripheral components such as aread only memory (ROM) and a random access memory (RAM). Further, thetravel controller 10 includes a parking operation assist unit thatperforms a drive assist process for parking.

In the process of the travel controller 10, the parking operation assistunit functionally includes processes of a peripheral environmentrecognition information calculation unit 10A, a vehicle speedcalculation unit 10B, a steering angle calculation unit 10C, and asteering angle speed calculation unit 10D, as illustrated in FIG. 2. Inaddition, the parking operation assist unit functionally includesprocesses of a shift position calculation unit 10E, a brake pedaloperation information calculation unit 10F, an accelerator operationamount calculation unit 10G, an accelerator operation speed calculationunit 10H, and an acceleration suppression control content calculationunit 10I. Furthermore, the parking operation assist unit functionallyincludes processes of an acceleration suppression instruction valuecalculation unit 10J, and a target throttle valve opening degreecalculation unit 10K. These functions may be configured by one, two ormore programs.

The peripheral environment recognition information calculation unit 10Aforms a peripheral image (overlooking image) of the vehicle V seen froman upper side of the vehicle V based on an individual image signalreceived from the peripheral environment recognition sensor 14. Further,the peripheral environment recognition information calculation unit 10Ais configured to output an information signal including the formedoverlooking image (also referred to as an “overlooking image signal” inthe following description) to the acceleration suppression controlcontent calculation unit 10I.

Here, the overlooking image is formed by synthesizing images captured bythe respective cameras (front camera 14F, right side camera 14SR, leftside camera 14SL, and rear camera 14R), for example. Further, theoverlooking image is configured to include an image indicating a roadsign such as a line of a parking frame (also referred to as a “parkingframe line” in the following description) displayed on a road surface,for example.

The vehicle speed calculation unit 10B calculates a speed (vehiclespeed) of the vehicle V from a rotational speed of the vehicle wheel Wbased on a vehicle wheel speed signal received from the vehicle wheelspeed sensor 16. Further, the vehicle speed calculation unit 10B isconfigured to output an information signal including the calculatedspeed (also referred to as a “vehicle speed calculation value signal” inthe following description) to the acceleration suppression controlcontent calculation unit 10I.

The steering angle calculation unit 10C is configured to calculate anoperation amount (rotation angle) with respect to the neutral positionof the steering wheel 28 from the current rotation angle of the steeringwheel 28 based on a current steering angle signal received from thesteering angle sensor 18. Further, the steering angle calculation unit10C is configured to output an information signal including thecalculated operation amount with respect to the neutral position (alsoreferred to as a “steering angle signal” in the following description)to the acceleration suppression control content calculation unit 10I.

The steering angle speed calculation unit 10D is configured to performdifferential processing with respect to the current steering angleincluded in the current steering angle signal received from the steeringangle sensor 18, to calculate a steering angle speed of the steeringwheel 28. Further, the steering angle speed calculation unit 10D isconfigured to output an information signal including the calculatedsteering angle speed (also referred to as a “steering angle speedsignal” in the following description) to the acceleration suppressioncontrol content calculation unit 10I.

The shift position calculation unit 10E is configured to determine acurrent shift position based on a shift position signal received fromthe shift position sensor 20. Further, the shift position calculationunit 10E is configured to output an information signal including thecalculated current shift position (also referred to as a “current shiftposition signal” in the following description) to the accelerationsuppression control content calculation unit 10I.

The brake pedal operation information calculation unit 10F is configuredto calculate a depression amount of the brake pedal 30 with reference toa state where the depression amount is “0”, based on a brake openingdegree signal received from the brake operation detection sensor 22.Further, the brake pedal operation information calculation unit 10F isconfigured to output an information signal including the calculateddepression amount of the brake pedal 30 (also referred to as a“braking-side depression amount signal” in the following description) tothe acceleration suppression control content calculation unit 10I.

The accelerator operation amount calculation unit 10G is configured tocalculate a depression amount of the accelerator pedal 32 with referenceto a state where the depression amount is “0”, based on an acceleratorpedal opening degree signal received from the accelerator operationdetection sensor 24. Further, the accelerator operation amountcalculation unit 10G is configured to output an information signalincluding the calculated depression amount of the accelerator pedal 32(also referred to as a “driving-side depression amount signal” in thefollowing description) to the acceleration suppression control contentcalculation unit 10I, the acceleration suppression instruction valuecalculation unit 10J, and the target throttle valve opening degreecalculation unit 10K.

The accelerator operation speed calculation unit 10H is configured toperform differential processing with respect to the opening degree ofthe accelerator pedal 32 included in the accelerator pedal openingdegree signal received from the accelerator operation detection sensor24, to calculate an operation speed of the accelerator pedal 32.Further, the accelerator operation speed calculation unit 10H isconfigured to output an information signal including the calculatedoperation speed of the accelerator pedal 32 (also referred to as an“accelerator operation speed signal” in the following description) tothe acceleration suppression instruction value calculation unit 10J.

The acceleration suppression control content calculation unit 10I isconfigured to receive inputs of the above-described various informationsignals (overlooking image signal, vehicle speed calculation valuesignal, steering angle signal, steering angle speed signal, currentshift position signal, braking-side depression amount signal,driving-side depression amount signal, vehicle position signal, andtravel road information signal). Further, an acceleration suppressionoperation condition determination result, an acceleration suppressioncontrol start timing, and an acceleration suppression control amountwhich will be described later are calculated based on the receivedvarious information signals. Further, the acceleration suppressioncontrol content calculation unit 10I outputs an information signalincluding the calculated parameters to the acceleration suppressioninstruction value calculation unit 10J.

A detailed configuration of the acceleration suppression control contentcalculation unit 10I and the process performed by the accelerationsuppression control content calculation unit 10I will be describedlater.

The acceleration suppression instruction value calculation unit 10J isconfigured to receive inputs of the above-described driving-sidedepression amount signal and the accelerator operation speed signal, andinputs of an acceleration suppression operation condition determinationresult signal, an acceleration suppression control start timing signal,and an acceleration suppression control amount signal which will bedescribed later. Further, the acceleration suppression instruction valuecalculation unit 10J is configured to calculate an accelerationsuppression instruction value which is an instruction value forsuppressing an acceleration instruction value depending on thedepression amount (driving force operation amount) of the acceleratorpedal 32. Further, the acceleration suppression instruction valuecalculation unit 10J is configured to output an information signalincluding the calculated acceleration suppression instruction value(also referred to as an “acceleration suppression instruction valuesignal” in the following description) to the target throttle valveopening degree calculation unit 10K.

Further, the acceleration suppression instruction value calculation unit10J is configured to calculate a normal acceleration instruction valuewhich is an instruction value used in a normal acceleration control incontent of the received acceleration suppression operation conditiondetermination result signal. Further, the acceleration suppressioninstruction value calculation unit 10J is configured to output aninformation signal including the calculated normal accelerationinstruction value (also referred to as a “normal accelerationinstruction value signal” in the following description) to the targetthrottle valve opening degree calculation unit 10K.

The process performed by the acceleration suppression instruction valuecalculation unit 10J will be described later.

The target throttle valve opening degree calculation unit 10K isconfigured to receive an input of the driving-side depression amountsignal, and an input of the acceleration suppression instruction valuesignal or the normal acceleration instruction value signal. Further, thetarget throttle valve opening degree calculation unit 10K is configuredto calculate an opening degree of a target throttle valve which is anopening degree of a throttle valve depending on the depression amount ofthe accelerator pedal 32 or the acceleration suppression instructionvalue based on the depression amount of the accelerator pedal 32, andbased on the acceleration suppression instruction value or the normalacceleration instruction value. Further, the target throttle valveopening degree calculation unit 10K is configured to output aninformation signal including the calculated opening degree of the targetthrottle valve (also referred to as a “target throttle valve openingdegree signal” in the following description) to the engine controller12.

Further, when the acceleration suppression instruction value includes anacceleration suppression control start timing instruction value whichwill be described later, the target throttle valve opening degreecalculation unit 10K is configured to output the target throttle valveopening degree signal to the engine controller 12 based on theacceleration suppression control start timing which will be describedlater.

The process performed by the target throttle valve opening degreecalculation unit 10K will be described later.

(Configuration of the Acceleration Suppression Control ContentCalculation Unit 10I)

Next, a detailed configuration of the acceleration suppression controlcontent calculation unit 10I will be described with reference to FIG. 3and FIG. 4A to FIG. 4P, while referring to FIG. 1 and FIG. 2. FIG. 3 isa block diagram illustrating the configuration of the accelerationsuppression control content calculation unit 10I.

As illustrated in FIG. 3, the acceleration suppression control contentcalculation unit 10I includes an acceleration suppression operationcondition determination unit 34, a parking frame certainty degreecalculation unit 36, a parking frame entering certainty degreecalculation unit 38, and a total certainty degree calculation unit 40.In addition, the acceleration suppression control content calculationunit 10I includes an acceleration suppression control start timingcalculation unit 42 and an acceleration suppression control amountcalculation unit 44.

The acceleration suppression operation condition determination unit 34is configured to determine whether or not an operation condition for anacceleration suppression control is established, and outputs aninformation signal including the determination result (also referred toas an “acceleration suppression operation condition determination resultsignal” in the following description) to the acceleration suppressioninstruction value calculation unit 10J. Here, the accelerationsuppression control is a control for suppressing the accelerationinstruction value for accelerating the vehicle V according to thedepression amount of the accelerator pedal 32.

The process of determining whether or not the operation condition forthe acceleration suppression control is established by the accelerationsuppression operation condition determination unit 34 will be describedlater.

The parking frame certainty degree calculation unit 36 is configured tocalculate a parking frame certainty degree indicating the degree ofcertainty that a parking frame is present in a travel direction of thevehicle V. Further, the parking frame certainty degree calculation unit36 is configured to output an information signal including thecalculated parking frame certainty degree (also referred to as a“parking frame certainty degree signal” in the following description) tothe total certainty degree calculation unit 40.

Here, the parking frame certainty degree calculation unit 36 isconfigured to calculate the parking frame certainty degree withreference to a variety of information included in the overlooking imagesignal, the vehicle speed calculation value signal, the current shiftposition signal, the vehicle position signal, and the travel roadinformation signal.

Further, the parking frame which is a calculation target of thecertainty degree in the parking frame certainty degree calculation unit36 includes plural patterns as illustrated in FIG. 4A to FIG. 4P, forexample. FIG. 4A to FIG. 4P are diagrams illustrating patterns of theparking frame which is the calculation target of the parking framecertainty degree in the parking frame certainty degree calculation unit36. The process of calculating the parking frame certainty degree by theparking frame certainty degree calculation unit 36 will be describedlater.

The parking frame entering certainty degree calculation unit 38 isconfigured to calculate a parking frame entering certainty degreeindicating the degree of certainty that the vehicle V enters the parkingframe. Further, the parking frame entering certainty degree calculationunit 38 outputs an information signal including the calculated parkingframe entering certainty degree (also referred to as a “parking frameentering certainty degree signal” in the following description) to thetotal certainty degree calculation unit 40.

Here, the parking frame entering certainty degree calculation unit 38 isconfigured to calculate the parking frame entering certainty degree withreference to a variety of information included in the overlooking imagesignal, the vehicle speed calculation value signal, the current shiftposition signal, and the steering angle signal. The process ofcalculating the parking frame entering certainty degree by the parkingframe entering certainty degree calculation unit 38 will be describedlater.

The total certainty degree calculation unit 40 is configured to receiveinputs of the parking frame certainty degree signal and the parkingframe entering certainty degree signal, and calculates a total certaintyfactor indicating a total degree of certainty of the parking framecertainty degree and the parking frame entering certainty degree.Further, the total certainty degree calculation unit 40 is configured tooutput an information signal including the calculated total certaintydegree (also referred to as a “total certainty degree signal” in thefollowing description) to the acceleration suppression control starttiming calculation unit 42 and the acceleration suppression controlamount calculation unit 44. The process of calculating the totalcertainty degree by the total certainty degree calculation unit 40 willbe described later.

The acceleration suppression control start timing calculation unit 42 isconfigured to calculate an acceleration suppression control start timingwhich is a timing when the acceleration suppression control is started.Further, the acceleration suppression control start timing calculationunit 42 is configured to output an information signal including thecalculated acceleration suppression control start timing (also referredto as an “acceleration suppression control start timing signal” in thefollowing description) to the acceleration suppression instruction valuecalculation unit 10J.

Here, the acceleration suppression control start timing calculation unit42 is configured to calculate the acceleration suppression control starttiming with reference to a variety of information included in the totalcertainty degree signal, the braking-side depression amount signal, thevehicle speed calculation value signal, the current shift positionsignal, and the steering angle signal. The process of calculating theacceleration suppression control start timing by the accelerationsuppression control start timing calculation unit 42 will be describedlater.

The acceleration suppression control amount calculation unit 44 isconfigured to calculate an acceleration suppression control amount whichis a control amount for suppressing the acceleration instruction valuedepending on the depression amount of the accelerator pedal 32. Further,the acceleration suppression control amount calculation unit 44 isconfigured to output an information signal including the calculatedacceleration suppression control amount (also referred to as an“acceleration suppression control amount signal” in the followingdescription) to the acceleration suppression instruction valuecalculation unit 10J.

Here, the acceleration suppression control amount calculation unit 44 isconfigured to calculate the acceleration suppression control amount withreference to a variety of information included in the total certaintydegree signal, the braking-side depression amount signal, the vehiclespeed calculation value signal, the current shift position signal, andthe steering angle signal. The process of calculating the accelerationsuppression control amount by the acceleration suppression controlamount calculation unit 44 will be described later.

(Process Performed by the Acceleration Suppression Control ContentCalculation Unit 10I)

Next, the process performed by the acceleration suppression controlcontent calculation unit 10I will be described with reference to FIG. 5to FIG. 14, while referring to FIG. 1 to FIG. 4P.

The process of determining whether or not the operation condition forthe acceleration suppression control (also referred to as an“acceleration suppression operation condition” in the followingdescription) is established by the acceleration suppression operationcondition determination unit 34 will be described using FIG. 5 and FIG.7, while referring to FIG. 1 to FIG. 4P.

FIG. 5 is a flowchart illustrating the process of determining whether ornot the acceleration suppression operation condition is established bythe acceleration suppression operation condition determination unit 34.The acceleration suppression operation condition determination unit 34performs the following process for each predetermined sampling time (forexample, 10 msec).

As illustrated in FIG. 5, if the acceleration suppression operationcondition determination unit 34 starts the process (START), first, instep S100, a process of acquiring a peripheral image of the vehicle V(“vehicle peripheral image acquisition process” in the figure) isperformed. After the process of acquiring the peripheral image of thevehicle V is performed in step S100, the process performed by theacceleration suppression operation condition determination unit 34progresses to step S102. The peripheral image of the vehicle V isacquired with reference to a peripheral overlooking image of the vehicleV included in an overlooking image signal received from the peripheralenvironment recognition information calculation unit 10A.

In step S102, a process of determining the presence or absence of aparking frame (“parking frame presence/absence determination process” inthe figure) is performed based on the image acquired in step S100.

The process of determining the presence or absence of the parking frameis performed by determining whether or not a white line (parking frameline) or the like for specifying the parking frame is present in apredetermined distance or area with reference to the vehicle V, forexample. Further, as a process of recognizing the parking frame linefrom the image acquired in step S100, for example, various known methodssuch as edge detection may be used.

Hereinafter, a parking frame line recognition method due to edgedetection will be described with reference to FIG. 6A to FIG. 6C. FIG.6A to FIG. 6C are schematic diagrams schematically illustrating theparking frame line recognition method due to edge detection.

As illustrated in FIG. 6A, when detecting parking frame lines Lm and Ln,in an area indicating a captured image, scanning is performed in alateral direction. In image scanning, for example, a black-and-whiteimage obtained by digitizing the captured image, or the like is used.FIG. 6A is a diagram illustrating the captured image.

Since the parking frame line is displayed with white color or the likewhich is sufficiently brighter than a road surface, the luminancethereof is higher than that of the road surface. Thus, as illustrated inFIG. 6B, in a boundary portion where the road surface transits to theparking frame line, a positive edge where the luminance rapidlyincreases is detected. FIG. 6B is a graph illustrating a luminancechange of pixels of an image when scanning is performed from the leftside to the right side, and FIG. 6C is a diagram illustrating a capturedimage, similarly to FIG. 6A. Further, in FIG. 6B, the positive edge isrepresented as sign “E₊”, and in FIG. 6C, the positive edge is indicatedby a thick solid line with sign “E₊”.

Further, in a boundary portion where the parking frame line transits tothe road surface, a negative edge where the luminance rapidly decreasesis detected. In FIG. 6B, the negative edge is represented as sign “E⁻”,and in FIG. 6C, the negative edge is indicated by a thick dotted linewith sign “E⁻”.

Further, in the process of recognizing the parking frame line, one pairof adjacent edges is detected in the order of the positive edge (E₊) andthe negative edge (E⁻) with respect to the scanning direction, and thus,it is determined that the parking frame line is present.

As the process of determining the presence or absence of the parkingframe, a process performed when the parking frame certainty degreecalculation unit 36 calculates the parking frame certainty degree may beused.

In step S102, when it is determined that the parking frame is present(“Yes” in the figure), the process performed by the accelerationsuppression operation condition determination unit 34 progresses to stepS104.

On the other hand, in step S102, when it is determined that the parkingframe is not present (“No” in the figure), the process performed by theacceleration suppression operation condition determination unit 34progresses to step S120.

In step S104, a process of acquiring the vehicle speed of the vehicle V(“vehicle speed information acquisition process” in the figure) isperformed with reference to a vehicle speed calculation value signalreceived from the vehicle speed calculation unit 10B. After the processof acquiring the vehicle speed of the vehicle V is performed in stepS104, the process performed by the acceleration suppression operationcondition determination unit 34 progresses to step S106.

In step S106, a process (“vehicle speed condition determination process”in the figure) of determining whether or not a condition where thevehicle speed of the vehicle V is less than a predetermined vehiclespeed threshold value is established based on the vehicle speed acquiredin step S104 is performed.

In the present embodiment, as an example, a case where the vehicle speedthreshold value is set to 15 km/h will be described. Further, thevehicle speed threshold value is not limited to 15 km/h, and forexample, may be changed according to specification of the vehicle V suchas braking performance of the vehicle V. Further, for example, thevehicle speed threshold value may be changed by traffic laws or the likeof a place (nation or the like) where the vehicle V is traveling.

In step S106, when it is determined that the condition where the vehiclespeed of the vehicle V is less than the vehicle speed threshold value isestablished (“Yes” in the figure), the process performed by theacceleration suppression operation condition determination unit 34progresses to step S108.

On the other hand, in step S106, when it is determined that thecondition where the vehicle speed of the vehicle V is less than thevehicle speed threshold value is not established (“No” in the figure),the process performed by the acceleration suppression operationcondition determination unit 34 progresses to step S120.

In step S108, a process of acquiring information on a depression amount(operation amount) of the brake pedal 30 (“brake pedal operation amountinformation acquisition process” in the figure) is performed withreference to a braking-side depression amount signal received from thebrake pedal operation information calculation unit 10F. After theprocess of obtaining the information on the depression amount (operationamount) of the brake pedal 30 is performed in step S108, the processperformed by the acceleration suppression operation conditiondetermination unit 34 progresses to step S110.

In step S110, a process of determining whether or not the brake pedal 30is operated (“brake pedal operation determination process” in thefigure) based on the depression amount of the brake pedal 30 acquired instep S108 is performed.

In step S110, when it is determined that the brake pedal 30 is notoperated (“No” in the figure), the process performed by the accelerationsuppression operation condition determination unit 34 progresses to stepS112.

On the other hand, in step S110, when it is determined that the brakepedal 30 is operated (“Yes” in the figure), the process performed by theacceleration suppression operation condition determination unit 34progresses to step S120.

In step S112, a process of acquiring information on a depression amount(operation amount) of the accelerator pedal 32 (“accelerator pedaloperation amount information acquisition process” in the figure) isperformed with reference to a driving-side depression amount signalreceived from the accelerator operation amount calculation unit 10G.After the process of acquiring information on the depression amount(operation amount) of the accelerator pedal 32 is performed in stepS112, the process performed by the acceleration suppression operationcondition determination unit 34 progresses to step S114.

In step S114, a process of determining whether or not a condition wherethe depression amount (operation amount) of the accelerator pedal 32 isequal to or greater than a predetermined accelerator operation amountthreshold value is established (“accelerator pedal operationdetermination process” in the figure) is performed. Here, the process ofstep S114 is performed based on the depression amount of the acceleratorpedal 32 acquired in step S112.

In the present embodiment, as an example, a case where the acceleratoroperation amount threshold value is set to an operation amountcorresponding to 3% of the opening degree of the accelerator pedal 32will be described. Further, the accelerator operation amount thresholdvalue is not limited to the operation amount corresponding to 3% of theopening degree of the accelerator pedal 32, and for example, may bechanged by specification of the vehicle V such as braking performance ofthe vehicle V.

In step S114, when it is determined that the condition where thedepression amount (operation amount) of the accelerator pedal 32 isequal to or greater than the accelerator operation amount thresholdvalue is established (“Yes” in the figure), the process performed by theacceleration suppression operation condition determination unit 34progresses to step S116.

On the other hand, in step S114, when it is determined that thecondition where the depression amount (operation amount) of theaccelerator pedal 32 is equal to or greater than the acceleratoroperation amount threshold value is not established (“No” in thefigure), the process performed by the acceleration suppression operationcondition determination unit 34 progresses to step S120.

In step S116, a process of acquiring information for determining whetheror not the vehicle V enters the parking frame (“parking frame enteringdetermination information acquisition process” in the figure) isperformed. Here, in the present embodiment, as an example, a case whereit is determined whether or not the vehicle V enters the parking framebased on a steering angle of the steering wheel 28, an angle formed bythe vehicle V and the parking frame, and a distance between the vehicleV and the parking frame will be described. After the process ofacquiring information for determining whether or not the vehicle Venters the parking frame is performed in step S116, the processperformed by the acceleration suppression operation conditiondetermination unit 34 progresses to step S118.

Here, a specific example performed in step S116 will be described. Instep S116, a rotation angle (steering angle) of the steering wheel 28 isacquired with reference to a steering angle signal received from thesteering angle calculation unit 10C. In addition, an angle α formed bythe vehicle V and a parking frame L0, and a distance D between thevehicle V and the parking frame L0 are acquired based on a peripheraloverlooking image of the vehicle V included in an overlooking imagesignal received from the peripheral environment recognition informationcalculation unit 10A.

Here, the angle α is set as an absolute value of an intersection anglebetween a straight line X and a frame line L1 and a line on a parkingframe L0 side, as illustrated in FIG. 7, for example. FIG. 7 is adiagram illustrating the vehicle V, the parking frame L0, and thedistance D between the vehicle V and the parking frame L0.

Further, the straight line X is a straight line (straight line extendingin a travel direction) in a longitudinal direction of the vehicle V,which passes through the center of the vehicle V, and the frame line L1is a part of space line of the parking frame L0, which is parallel to orapproximately parallel to the longitudinal direction of the vehicle Vwhen parking is completed at the parking frame L0. In addition, the lineon the parking frame L0 side is a line on the parking frame L0 sideformed by an extended line of L1.

Further, the distance D is a distance between a center point PF on afront end surface of the vehicle V and a center point PP of an entranceL2 of the parking frame L0, as illustrated in FIG. 7, for example. Here,the distance D becomes a negative value after the front end surface ofthe vehicle V passes through the entrance L2 of the parking frame L0.The distance D may be set to zero after the front end surface of thevehicle V passes through the entrance L2 of the parking frame L0.

Here, the location of the vehicle V for specifying the distance D is notlimited to the center point PF, and for example, may be a predeterminedlocation of the vehicle V and a predetermined location of the entranceL2. In this case, the distance D is a distance between the predeterminedlocation of the vehicle V and the predetermined position of the entranceL2.

As described above, in step S116, as the information for determiningwhether or not the vehicle V enters the parking frame L0, the steeringangle, the angle α between the vehicle V and the parking frame L0, andthe distance D between the vehicle V and the parking frame L0 areacquired.

In step S118, a process of determining whether or not the vehicle Venters the parking frame (“parking frame entering determination process”in the figure) is performed based on the information acquired in stepS116. In step S118, when it is determined that the vehicle V does notenter the parking frame (“No” in the figure), the process performed bythe acceleration suppression operation condition determination unit 34progresses to step S120.

On the other hand, in step S118, when it is determined that the vehicleV enters the parking frame (“Yes” in the figure), the process performedby the acceleration suppression operation condition determination unit34 progresses to step S122.

Here, a specific example of the process performed in step S118 will bedescribed. In step S118, for example, when all of the following threeconditions (A1 to A3) are satisfied, it is determined that the vehicle Venters the parking frame.

Condition A1: A time elapsed after the value of the steering angledetected in step S116 is equal to or greater than a predeterminedsetting steering angle value (for example, 45 deg) is within apredetermined setting time (for example, 20 sec).

Condition A2: The angle cc between the vehicle V and the parking frameL0 is equal to or smaller than a predetermined setting angle (forexample, 40 deg).

Condition A3: The distance D between the vehicle V and the parking frameL0 is equal to or shorter than a predetermined setting distance (forexample, 3 m).

As the process of determining whether or not the vehicle V enters theparking frame, a process performed when the parking frame enteringcertainty degree is calculated by the parking frame entering certaintydegree calculation unit 38 may be used.

Further, the process used for determination of whether or not thevehicle V enters the parking frame is not limited to the process usingthe plural conditions as described above, and a determination process inone or more conditions among the above-described three conditions may beused. Further, the process of determining whether or not the vehicle Venters the parking frame may be used using the vehicle speed of thevehicle V.

In step S120, a process of generating the acceleration suppressionoperation condition determination result signal as an information signalincluding the determination result that the acceleration suppressioncontrol operation condition is not established (“accelerationsuppression operation condition non-establishment” in the figure) isperformed. After the process of generating the acceleration suppressionoperation condition determination result signal including thedetermination result that the acceleration suppression control operationcondition is not established is performed in step S120, the processperformed by the acceleration suppression operation conditiondetermination unit 34 progresses to step S124.

In step S122, a process of generating the acceleration suppressionoperation condition determination result signal as an information signalincluding the determination result that the acceleration suppressioncontrol operation condition is established (“acceleration suppressionoperation condition establishment” in the figure) is performed. Afterthe process of generating the acceleration suppression operationcondition determination result signal including the determination resultthat the acceleration suppression control operation condition isestablished is performed in step S122, the process performed by theacceleration suppression operation condition determination unit 34progresses to step S124.

In step S124, a process of outputting the acceleration suppressionoperation condition determination result signal generated in step S120or step S122 to the acceleration suppression instruction valuecalculation unit 10J (“acceleration suppression operation conditiondetermining result output” in the figure) is performed. After theprocess of outputting the acceleration suppression operation conditiondetermination result signal to the acceleration suppression instructionvalue calculation unit 10J is performed in step S124, the processperformed by the acceleration suppression operation conditiondetermination unit 34 returns to the process of step S100 (RETURN).

The process of calculating the parking frame certainty degree by theparking frame certainty degree calculation unit 36 will be describedwith reference to FIG. 8 to FIG. 10, while referring to FIG. 1 to FIG.7. FIG. 8 is a flowchart illustrating the process of calculating theparking frame certainty degree by the parking frame certainty degreecalculation unit 36. The parking frame certainty degree calculation unit36 performs the following processes for each predetermined sampling time(for example, 10 msec).

As illustrated in FIG. 8, if the parking frame certainty degreecalculation unit 36 starts the process (START), first, in step S200, aprocess of calculating (setting) the level of the parking framecertainty degree as a lowest value (level 0) (“level 0” in the figure)is performed. After the process of calculating the parking framecertainty degree to the level 0 is performed in step S200, the processperformed by the parking frame certainty degree calculation unit 36progresses to step S202.

In step S202, a process of acquiring a peripheral overlooking image ofthe vehicle V included in an overlooking image signal received from theperipheral environment recognition information calculation unit 10A(“peripheral image acquisition” in the figure) is performed. After theprocess of acquiring the peripheral overlooking image of the vehicle Vis performed in step S202, the process performed by the parking framecertainty degree calculation unit 36 progresses to step S204.

In step S204, a process of extracting a determination factor used forcalculating the parking frame certainty degree from the overlookingimage acquired in step S202 (“determination factor extraction” in thefigure) is performed. After the process of extracting the determinationfactor from the overlooking image is performed in step S204, the processperformed by the parking frame certainty degree calculation unit 36progresses to step S206.

Here, the determination factor represents a line (white line or thelike) marked on a road surface, such as a parking frame line, and forexample, when state of the line satisfies all the following threeconditions (B1 to B3), the line is extracted as the determinationfactor.

Condition B1: When a broken portion is present in the line marked on theroad surface, the broken portion is a portion where the marked line isblurred (for example, a portion of which clarity is lower than that ofthe line and higher than that of the road surface).

Condition B2: The width of the line marked on the road surface is equalto or greater than a predetermined setting width (for example, 10 cm).The setting width is not limited to 10 cm, and for example, may bechanged according to a traffic law or the like of a place (nation or thelike) where the vehicle V is traveling.

Condition B3: The length of the line marked on the road surface is equalto or greater than a predetermined setting mark line length (forexample, 2.5 m). The setting mark line length is not limited to 2.5 m,and for example, may be changed according to a traffic law of a place(nation or the like) where the vehicle V is traveling.

In step S206, a process of determining whether or not the determinationfactor extracted in step S204 is suitable for a condition of a line forforming the parking frame line (“suitable for parking frame condition?”in the figure) is performed.

In step S206, when it is determined whether or not the determinationfactor extracted in step S204 is not suitable for the condition of theline for forming the parking frame line (“No” in the figure), theprocess performed by the parking frame certainty degree calculation unit36 progresses to step S200.

On the other hand, in step S206, when it is determined whether or notthe determination factor extracted in step S204 is suitable for thecondition of the line for forming the parking frame line (“Yes” in thefigure), the process performed by the parking frame certainty degreecalculation unit 36 progresses to step S208. The process performed instep S206 is performed with reference to the overlooking image signalreceived from the peripheral environment recognition informationcalculation unit 10A, for example.

Here, a specific example of the process performed in step S206 will bedescribed with reference to FIG. 9A to FIG. 9D. FIG. 9A to FIG. 9D arediagrams illustrating content of the process performed by the parkingframe certainty degree calculation unit 36. In FIG. 9A to FIG. 9D, anarea indicating an image captured by the front camera 14F among theoverlooking images is represented as sign “PE”.

In step S206, first, adjacent two lines displayed on the same screen isspecified as one set (also referred to as “pairing” in the followingdescription) from the lines marked on the road surface which is thedetermination factor extracted in step S204. When three or more linesare displayed on the same screen, two or more sets are respectivelyspecified by adjacent two lines, with respect to the three or morelines.

Next, when all of the following four conditions (C1 to C4) are satisfiedwith respect to two lines which are paired, it is determined that thedetermination factor extracted in step S204 is suitable for thecondition of the line for forming the parking frame line.

Condition C1: As illustrated in FIG. 9A, a width WL between two lineswhich are paired (represented as sign “La” and sign “Lb” in the figure)is equal to or greater than a predetermined setting pairing width (forexample, 2.5 m). The setting pairing width is not limited to 2.5 m, andfor example, may be changed according to a traffic law or the like of aplace (nation or the like) where the vehicle V is traveling.

Condition C2: As illustrated in FIG. 9B, an angle (parallelism) formedby a line La and a line Lb is equal to or smaller than a predeterminedsetting angle (for example, 3°). The setting angle is not limited to 3°,and for example, may be changed according to recognition performance orthe like of the peripheral environment recognition sensor 14. In FIG.9B, a reference line (line extending in a vertical direction in the areaPE) is indicated by a dashed line with sign “CLc”, a central axis lineof the line La is indicated by a dotted line with sign “CLa”, and acentral axis line of the line Lb is indicated by a dotted line with sign“CLb”. Further, an inclination angle of the central axis line CLa withrespect to the reference line CLc is represented as sign “θa”, and aninclination angle of the central axis line CLb with respect to thereference line CLc is represented as sign “θb”. Accordingly, if aconditional expression of |θa−θb|≦3° is established, Condition C2 issatisfied.

Condition C3: As illustrated in FIG. 9C, an angle θ formed by a straightline that connects an end portion (end portion on a lower side in thefigure) of a line La on a vehicle V side and an end portion of a line Lbon the vehicle V side, and the line L close to the vehicle V is equal toor greater than a predetermined setting deviation angle (for example,45°). The setting deviation angle is not limited to 45°, and forexample, may be changed according to recognition performance or the likeof the peripheral environment recognition sensor 14.

Condition C4: As illustrated in FIG. 9D, an absolute value (|W0−W1|) ofa difference between a width W0 of the line La and a width W1 of theline Lb is equal to or smaller than a predetermined setting line width(for example, 10 cm). The setting line width is not limited to 10 cm,and for example, may be changed according to recognition performance orthe like of the peripheral environment recognition sensor 14.

In a process of determining whether or not the above-described fourconditions (C1 to C4) are satisfied, when the length of at least one ofthe lines La and Lb is cut at a position of about 2 m, for example, theprocess is continued using a line of about 4 m obtained by extending avirtual line of about 2 m from the cut line.

In step S208, a process of determining whether or not the process ofstep S206 is continuously checked until a moving distance of the vehicleV after the process of step S206 is started reaches a predeterminedsetting moving distance (“suitable for continuous check?” in the figure)is performed. The setting moving distance is set within a range of 1 mto 2.5 m, for example, according to specification of the vehicle V.Further, the process of step S208 is performed with reference to theoverlooking image signal received from the peripheral environmentrecognition information calculation unit 10A and the vehicle speedcalculation value signal received from the vehicle speed calculationunit 10B, for example.

In step S208, when it is determined that the process of step S206 is notcontinuously checked (“No” in the figure), the process performed by theparking frame certainty degree calculation unit 36 progresses to stepS210.

On the other hand, in step S208, when it is determined that the processof step S206 is continuously checked (“Yes” in the figure), the processperformed by the parking frame certainty degree calculation unit 36progresses to step S212.

Here, in the process performed in step S208, for example, as illustratedin FIG. 10, the moving distance of the vehicle V is virtually calculatedaccording to a state where the process of step S206 is checked and astate where the process of step S206 is not checked. FIG. 10 is adiagram illustrating content of the process performed by the parkingframe certainty degree calculation unit 36. Further, in FIG. 10, in anarea of “check state”, the state where the process of step S206 ischecked is represented as “ON”, and the state where the process of stepS206 is not checked is represented as “OFF”. In addition, in FIG. 10,the virtually calculated moving distance of the vehicle V is representedas a “virtual travel distance”.

As illustrated in FIG. 10, in the “ON” state where the process of stepS206 is checked, the virtual travel distance increases. On the otherhand, in the “OFF” state where the process of step S206 is checked, thevirtual travel distance decreases.

In the present embodiment, as an example, a case where an inclination(increase gain) when the virtual travel distance increases is set to begreater than an inclination (decrease gain) when the virtual traveldistance decreases will be described. That is, if the state where the“check state” is “ON” and the state where the “check state” is “OFF” aremaintained for the same time, the virtual travel distance increases.

Further, when the virtual travel distance reaches the setting movingdistance without returning to an initial value (“0 m” in the figure), itis determined that the process of step S206 is continuously checked.

In step S210, a process of calculating the level of the parking framecertainty degree as a level (level 1) which is higher than the lowestvalue (level 0) by one step (“level 1” in the figure) is performed.After the process of calculating the parking frame certainty degree asthe level 1 is performed in step S210, the process performed by theparking frame certainty degree calculation unit 36 is terminated (END).

In step S212, with respect to the lines La and Lb where the process ofstep S206 is continuously checked, end points (end points on a near sideor end points on a far side) positioned on the same side with referenceto the vehicle V are respectively detected. Further, a process ofdetermining whether or not the end points positioned on the same sideface each other along a direction of the width WL (“facing of near andfar end points suitable?” in the figure) is performed. The process ofstep S212 is performed with respect to the overlooking image signalreceived from the peripheral environment recognition informationcalculation unit 10A and the vehicle speed calculation value signalreceived from the vehicle speed calculation unit 10B.

In step S212, when it is determined that the end points positioned onthe same side do not face each other along the direction of the width WL(“No” in the figure), the process performed by the parking framecertainty degree calculation unit 36 progresses to step S214.

On the other hand, in step S212, when it is determined that the endpoints positioned on the same side face each other along the directionof the width WL (“Yes” in the figure), the process performed by theparking frame certainty degree calculation unit 36 progresses to stepS216.

In step S214, a process of calculating the level of the parking framecertainty degree as a level (level 2) which is higher than the lowestvalue (level 0) by two steps (“level 2” in the figure) is performed.After the process of calculating the parking frame certainty degree asthe level 2 is performed in step S214, the process performed by theparking frame certainty degree calculation unit 36 is terminated (END).

In step S216, with respect to the lines La and Lb where it is determinedin the process of step S212 that the end points positioned on the sameside face each other along the direction of the width WL, end pointspositioned on the other side are detected. That is, when the end pointson the near side (one side) are detected with respect to the lines Laand Lb in the process of step S212, in step S216, the end points on thefar side (the other side) are detected with respect to the lines La andLb. Further, a process of determining whether or not the end pointspositioned on the other side face each other along the direction of thewidth WL (“facing of opposite end points suitable?” in the figure) isperformed. The process of step S216 is performed with respect to theoverlooking image signal received from the peripheral environmentrecognition information calculation unit 10A and the vehicle speedcalculation value signal received from the vehicle speed calculationunit 10B.

When detecting the end points of the lines La and Lb, an end point of astraight line such as an end point of a line illustrated in FIG. 4A, aU-shaped end point such as an upper end point of a line illustrated inFIG. 4G, and an intersection between a double line and a lateral lineillustrated in FIG. 4O are collectively processed as an end point of onestraight line. Similarly, an end point of a double line such as an upperend point of a line illustrated in FIG. 4H, and an end point where a gapportion is formed in a U-shaped curve such as an upper end point of aline illustrated in FIG. 4M are collectively processed as an end pointof one straight line.

Further, when detecting the end points of the lines La and Lb, anintersection between a double line which is obliquely extended in avertical direction and one straight line extended in a lateral directionillustrated in FIG. 4N is not processed (recognized) as an end point.This is because when detecting an end point, lateral scanning isperformed in an area where a captured image is displayed to detect theend point. Further, for example, since an area indicated by a whiteframe rectangle in FIG. 4P represents an object on a road such as apillar, an end point of an object is not detected, either.

In step S216, when it is determined that the end points positioned onthe other side do not face each other along the direction of the widthWL (“No” in the figure), the process performed by the parking framecertainty degree calculation unit 36 progresses to step S218.

On the other hand, in step S216, when it is determined that the endpoints positioned on the other side face each other along the directionof the width WL (“Yes” in the figure), the process performed by theparking frame certainty degree calculation unit 36 progresses to stepS220.

In step S218, a process of calculating the level of the parking framecertainty degree as a level (level 3) which is higher than the lowestvalue (level 0) by three steps (“level 3” in the figure) is performed.After the process of calculating the parking frame certainty degree asthe level 3 is performed in step S218, the process performed by theparking frame certainty degree calculation unit 36 is terminated (END).

In step S220, a process of calculating the level of the parking framecertainty degree as a level (level 4) which is higher than the lowestvalue (level 0) by four steps (“level 4” in the figure) is performed.After the process of calculating the parking frame certainty degree asthe level 4 is performed in step S220, the process performed by theparking frame certainty degree calculation unit 36 is terminated (END).

Accordingly, in the process of calculating the parking frame certaintydegree as the level 3, the parking frame certainty degree is calculatedwith respect to patterns of FIG. 4D, FIG. 4E, FIG. 4J, and FIG. 4K amongthe parking frames illustrated in FIG. 4A to FIG. 4P. Further, in theprocess of calculating the parking frame certainty degree as the level4, the parking frame certainty degree is calculated with respect to theother patterns excluding FIG. 4D, FIG. 4E, FIG. 4J, and FIG. 4K amongthe parking frames illustrated in FIG. 4A to FIG. 4P.

Particularly, when the pattern illustrated in FIG. 4A which is a parkingframe having a high possibility of being marked on a public road isspecified, or when a parking frame other than the pattern illustrated inFIG. 4A cannot be specified, the parking frame certainty degree may belimited as follows according to the width of the parking frame.

Specifically, for example, when the width of the parking frame is equalto or smaller than 2.6 m, the parking frame certainty degree maintainsthe initially calculated level, but when the width of the parking frameexceeds 2.6 m, the parking frame certainty degree is limited so as notto be calculated as the level 3 or higher. Thus, a configuration inwhich opposite broken lines marked on the public road are not easilydetected as the parking frame line is obtained.

The process in which the parking frame entering certainty degreecalculation unit 38 calculates the parking frame entering certaintydegree will be described with reference to FIG. 11 and FIG. 12, whilereferring to FIG. 1 to FIG. 10. FIG. 11 is a flowchart illustrating theprocess of calculating the parking frame entering certainty degree bythe parking frame entering certainty degree calculation unit 38. Theparking frame entering certainty degree calculation unit 38 performs thefollowing process for each predetermined sampling time (for example, 10msec).

As illustrated in FIG. 11, if the parking frame entering certaintydegree calculation unit 38 starts the process (START), first, in stepS300, a process of detecting a deviation amount between a rear wheelexpected locus of the vehicle V and the parking frame (“deviation amountdetection” in the figure) is performed. After the process of detectingthe deviation amount between the rear wheel expected locus of thevehicle V and the parking frame is performed in step S300, the processperformed by the parking frame entering certainty degree calculationunit 38 progresses to step S302. In the present embodiment, as anexample, a case where the unit of the deviation amount detected in stepS300 is set to cm will be described. Further, in the present embodiment,as an example, a case where the width of the parking frame is set to 2.5m will be described.

Here, in the process performed in step S300, for example, as illustratedin FIG. 12, a rear wheel expected locus TR of the vehicle V iscalculated, and an intersection TP between the calculated rear wheelexpected locus TR and an entrance L2 of a parking frame L0 iscalculated. Further, a distance Lfl between a left side frame line Lllof the parking frame L0 and the intersection TP, and a distance Lfrbetween a right side frame line Llr of the parking frame L0 and theintersection TP are calculated, and the distance Lfl is compared withthe distance Lfr. Further, a longer distance among the distance Lfl andthe distance Lfr is detected as a deviation amount between the rearwheel expected locus TR of the vehicle V and the parking frame L0. FIG.12 is a diagram illustrating content of the process of detecting thedeviation amount between the rear wheel expected locus TR of the vehicleV and the parking frame L0.

Further, when calculating the rear wheel expected locus TR of thevehicle V, a center point PR between the right rear wheel WRR and theleft rear wheel WRL in the vehicle width direction in the vehicle V isset as a reference point of the vehicle V. Further, a virtual movingpath of the center point PR is calculated using images captured by thefront camera 14F and the left side camera 14SL among the overlookingimages, the vehicle speed of the vehicle V, and the rotation angle(steering angle) of the steering wheel 28, to thereby calculate the rearwheel expected locus TR.

In step S302, for example, a process of detecting a parallelism betweena straight line X and a length direction (for example, retreatingdirection) of the parking frame L0 (“parallelism detection” in thefigure) is performed using the image captured by the front camera 14Famong the overlooking images. After the process of detecting theparallelism between the straight line X and the length direction of theparking frame L0 is performed in step S302, the process performed by theparking frame entering certainty degree calculation unit 38 progressesto step S304.

Here, the parallelism detected in step S302 is detected as an angle θapformed by a center line Y of the parking frame L0 and the straight lineX, as illustrated in FIG. 12. In step S302, when the vehicle V moves tothe parking frame L0 during retreating, for example, the process ofdetecting the parallelism between the straight line X and the lengthdirection of the parking frame L0 is performed using the image capturedby the rear camera 14R among the overlooking images. Here, the movingdirection (advancing or retreating) of the vehicle V is detected withreference to a current shift position signal, for example.

In step S304, a process of calculating a vehicle speed of the vehicle Vand a turning radius of the vehicle V using the rotation angle (steeringangle) of the steering wheel 28 (“turning radius calculation” in thefigure) is performed. After the process of calculating the turningradius of the vehicle V is performed in step S304, the process performedby the parking frame entering certainty degree calculation unit 38progresses to step S306.

In step S306, a process of determining whether or not the parallelism(θap) detected in step S302 is smaller than a predetermined parallelismthreshold value (for example, 15°) (“parallelism<parallelism thresholdvalue?” in the figure) is performed.

In step S306, when it is determined that the parallelism (θap) detectedin step S302 is equal to or greater than the parallelism threshold value(“No” in the figure), the process performed by the parking frameentering certainty degree calculation unit 38 progresses to step S308.

On the other hand, in step S306, when it is determined that theparallelism (θap) detected in step S302 is smaller than the parallelismthreshold value (“Yes” in the figure), the process performed by theparking frame entering certainty degree calculation unit 38 progressesto step S310.

In step S308, a process of determining whether or not the turning radiusdetected in step S304 is equal to or greater than a preset turningradius threshold value (for example, 100 [R]) (“turning radius>=turningradius threshold value?” in the figure) is performed.

In step S308, when it is determined that the turning radius detected instep S304 is smaller than the turning radius threshold value (“No” inthe figure), the process performed by the parking frame enteringcertainty degree calculation unit 38 progresses to step S312.

On the other hand, in step S308, when it is determined that the turningradius detected in step S304 is equal to or greater than the turningradius threshold value (“Yes” in the figure), the process performed bythe parking frame entering certainty degree calculation unit 38progresses to step S310.

In step S310, a process of determining whether or not the deviationamount detected in step S300 is equal to or greater than a predeterminedfirst threshold value (for example, 75 cm) (“deviation amount>=firstthreshold value?” in the figure) is performed. The first threshold valueis not limited to 75 cm, and for example, may be changed according tospecification of the vehicle V.

In step S310, when it is determined that the deviation amount detectedin step S300 is equal to or greater than the first threshold value(“Yes” in the figure), the process performed by the parking frameentering certainty degree calculation unit 38 progresses to step S314.

On the other hand, in step S310, when it is determined that thedeviation amount detected in step S300 is smaller than the firstthreshold value (“No” in the figure), the process performed by theparking frame entering certainty degree calculation unit 38 progressesto step S316.

In step S312, a process of determining whether or not the deviationamount detected in step S300 is equal to or greater than a predeterminedsecond threshold value (for example, 150 cm) (“deviation amount>=secondthreshold value?” in the figure) is performed. Here, the secondthreshold value is set to a value larger than the above-described firstthreshold value. The second threshold value is not limited to 150 cm,and for example, may be changed according to specification of thevehicle V.

In step S312, when it is determined that the deviation amount detectedin step S300 is equal to or greater than the second threshold value(“Yes” in the figure), the process performed by the parking frameentering certainty degree calculation unit 38 progresses to step S318.

On the other hand, in step S312, when it is determined that thedeviation amount detected in step S300 is smaller than the secondthreshold value (“No” in the figure), the process performed by theparking frame entering certainty degree calculation unit 38 progressesto step S314.

In step S314, a process of calculating (setting) the parking frameentering certainty degree as a low level (“entering certainty factor=lowlevel” in the figure) is performed. After the process of calculating theparking frame entering certainty degree as the low level is performed instep S314, the process performed by the parking frame entering certaintydegree calculation unit 38 is terminated (END).

In step S316, a process of calculating the parking frame enteringcertainty degree as a high level (“entering certainty degree=high level”in the figure) is performed. After the process of calculating theparking frame entering certainty degree as the high level is performedin step S316, the process performed by the parking frame enteringcertainty degree calculation unit 38 is terminated (END).

In step S318, a process of calculating the level of the parking frameentering certainty degree as a lowest value (level 0) (“enteringcertainty degree=level 0” in the figure) is performed. After the processof calculating the parking frame entering certainty degree as the level0 is performed in step S318, the process performed by the parking frameentering certainty degree calculation unit 38 is terminated (END).

As described above, the parking frame entering certainty degreecalculation unit 38 performs the process of calculating the parkingframe entering certainty degree as any level among the “level 0” whichis the lowest value, a “low level” which is a level higher than thelevel 0, and a “high level” which is a level higher than the low level.

When the vehicle V has a configuration in which a device (parking assistdevice) that assists a steering operation to the parking frame L0 for adriver is provided, for example, a configuration in which the level ofthe parking frame entering certainty degree easily increases when theparking assist device is in an ON state may be used.

Here, as the parking assist device, for example, there is a device thatdisplays on a monitor a peripheral situation using an overlooking imageor the like in order to perform parking, and a device that sets a targetparking position on a screen in order to guide a course for parking.Such devices are used by operating a switch that switches a screen formonitor-displaying the peripheral situation using the overlooking imageor the like, or a switch that switches a screen for setting the targetparking position on the screen. Further, a configuration in which whenthe switches are operated, the parking assist device enters the ON stateis used.

As a specific example of the configuration in which the level of theparking frame entering certainty degree easily increases, aconfiguration in which even if the parking frame entering certaintydegree is calculated as the “level 0” in the process of step S318, whenthe parking assist device is in the ON state, the parking frame enteringcertainty degree is corrected to the “low level” may be used. Further,for example, a configuration in which even if the parking frame enteringcertainty degree is calculated as the “low level” in the process of stepS314, when the parking assist device is in the ON state, the parkingframe entering certainty degree is corrected to the “high level” may beused. As the configuration in which the level of the parking frameentering certainty degree easily increases, for example, a configurationin which the parking frame entering certainty degree is calculated as apredetermined level (for example, “high level”) regardless of an actualentering situation to the parking frame may be used.

The process of calculating the total certainty degree by the totalcertainty degree calculation unit 40 will be described with reference toFIG. 13, while referring to FIG. 1 to FIG. 12. The total certaintydegree calculation unit 40 receives inputs of a parking frame certaintydegree signal and a parking frame entering certainty degree signal, andmakes a parking frame certainty degree included in the parking framecertainty degree signal, and a parking frame entering certainty degreeincluded in the parking frame entering certainty degree signal suitablefor a total certainty degree calculation map illustrated in FIG. 13.Further, a total certainty degree is calculated based on the parkingframe certainty degree and the parking frame entering certainty degree.

FIG. 13 is a diagram illustrating the total certainty degree calculationmap. Further, in FIG. 13, the parking frame certainty degree isrepresented as a “frame certainty degree”, and the parking frameentering certainty degree is represented as an “entering certaintydegree”. Further, the total certainty degree calculation map illustratedin FIG. 13 is a map used when the vehicle V is advancing.

As an example of the process of calculating the total certainty degreeby the total certainty degree calculation unit 40, when the parkingframe certainty degree is “level 3” and the parking frame enteringcertainty degree is “high level”, as illustrated in FIG. 13, the totalcertainty degree is calculated as “high”.

In the present embodiment, as an example, a case where if the totalcertainty degree calculation unit 40 performs the process of calculatingthe total certainty degree, a process of storing the calculated totalcertainty degree in a storing unit where data is not erased even when anignition switch is in an OFF state will be described. Here, as thestoring unit where the data is not erased even when the ignition switchis in the OFF state, a ROM or the like may be used.

Accordingly, in the present embodiment, at a time point when theignition switch is in the OFF state after the parking of the vehicle Vis completed and then enters an ON state when the vehicle V isrestarted, the total certainty degree that is immediately previouslycalculated is stored. Thus, it is possible to start the control based onthe immediately previously calculated total certainty degree from thetime point when the ignition switch enters the ON state when the vehicleV is restarted.

The process of calculating the acceleration suppression control starttiming by the acceleration suppression control start timing calculationunit 42 will be described with reference to FIG. 14, while referring toFIG. 1 to FIG. 13. The acceleration suppression control start timingcalculation unit 42 receives an input of the total certainty degreesignal, and makes the total certainty degree included in the totalcertainty degree signal suitable for an acceleration suppressioncondition calculation map illustrated in FIG. 14. Further, theacceleration suppression control start timing calculation unit 42calculates the acceleration suppression control start timing based onthe total certainty degree.

FIG. 14 is a diagram illustrating the acceleration suppression conditioncalculation map. Further, in FIG. 14, the acceleration suppressioncontrol start timing is represented as “suppression control start timing(opening degree of an accelerator pedal)” in an area of “accelerationsuppression condition”.

As an example of the process performed by the acceleration suppressioncontrol start timing calculation unit 42, when the total certaintydegree is “high”, as illustrated in FIG. 14, the accelerationsuppression control start timing is set to a timing when the openingdegree of the accelerator pedal 32 increases to reach “50%”. The openingdegree of the accelerator pedal 32 is set so that a state where theaccelerator pedal 32 is depressed (operated) to a maximum valuecorresponds to 100%.

The acceleration suppression control start timing illustrated in FIG. 14is exemplary, and for example, may be changed according to specificationof the vehicle V such as braking performance of the vehicle V. Further,for example, the acceleration suppression control start timing may bechanged according to a traffic law or the like of a place (nation or thelike) where the vehicle V is traveling.

The process of calculating the acceleration suppression control amountby the acceleration suppression control amount calculation unit 44 willbe described with reference to FIG. 1 to FIG. 14. The accelerationsuppression control amount calculation unit 44 receives an input of thetotal certainty degree signal, and makes the total certainty degreeincluded in the total certainty degree signal suitable for theacceleration suppression condition calculation map illustrated in FIG.14. The acceleration suppression control amount is calculated based onthe total certainty degree. In FIG. 14, the acceleration suppressioncontrol amount is represented as “suppression amount” in a unit of“acceleration suppression condition”.

As an example of the process performed by the acceleration suppressioncontrol amount calculation unit 44, when the total certainty degree is“high”, as illustrated in FIG. 14, the acceleration suppression controlamount is set as a control amount in which an actual opening degree ofthe accelerator pedal 32 is suppressed to an opening degree of athrottle valve of a “medium” level. In the present embodiment, as anexample, the opening degree of the throttle valve of the “medium” levelis set as an opening degree of a throttle valve in which the actualopening degree of the accelerator pedal 32 is suppressed to 25%.Similarly, an opening degree of a throttle valve of a “low” level is setas an opening degree of a throttle valve in which the actual openingdegree of the accelerator pedal 32 is suppressed to 50%, and an openingdegree of a throttle valve of a “high” level is set as an opening degreeof a throttle valve in which the actual opening degree of theaccelerator pedal 32 is suppressed to 10%.

The acceleration suppression control amount illustrated in FIG. 14 isexemplary, and for example, may be changed according to specification ofthe vehicle V such as braking performance of the vehicle V. Further, forexample, the acceleration suppression control amount may be changedaccording to a traffic law or the like of a place (nation or the like)where the vehicle V is traveling.

Further, the acceleration suppression control amount calculation unit 44makes the total certainty degree suitable for the accelerationsuppression condition calculation map, and sets the presence or absenceof a control for outputting alarm sound. When the alarm sound is to beoutput, for example, character information on the content that theacceleration suppression control is operated or visual information suchas a sign or light emission may be displayed on a display monitorprovided in the navigation unit 26.

(Process Performed by Acceleration Suppression Instruction ValueCalculation Unit 10J)

Next, the process of performing the acceleration suppression instructionvalue calculation unit 10J will be described with reference to FIG. 15,while referring to FIG. 1 to FIG. 14. FIG. 15 is a flowchartillustrating the process performed by the acceleration suppressioninstruction value calculation unit 10J. The acceleration suppressioninstruction value calculation unit 10J performs the following processfor each predetermined sampling time (for example, 10 msec).

As illustrated in FIG. 15, if the acceleration suppression instructionvalue calculation unit 10J starts the process (START), first, in stepS400, the acceleration suppression operation condition determinationresult signal received from the acceleration suppression control contentcalculation unit 10I is referenced. Further, a process of acquiring anacceleration suppression operation condition determination result(“acceleration suppression operation condition determination resultacquisition process” in the figure) is performed. After the process ofacquiring the acceleration suppression operation condition determinationresult is performed in step S400, the process performed by theacceleration suppression instruction value calculation unit 10Jprogresses to step S402.

In step S402, a process of acquiring information for calculating anacceleration suppression instruction value, in addition to theacceleration suppression operation condition determination resultacquired in step S400 (“acceleration suppression instruction valuecalculation information acquisition process” in the figure) isperformed. After the process of acquiring the information forcalculating the acceleration suppression instruction value is performedin step S402, the process performed by the acceleration suppressioninstruction value calculation unit 10J progresses to step S404.

The information for calculating the acceleration suppression instructionvalue refers to information included in the above-described accelerationsuppression control start timing signal, acceleration suppressioncontrol amount signal, driving-side depression amount signal, andaccelerator operation speed signal, for example.

In step S404, a process of determining whether or not the accelerationsuppression operation condition determination result acquired in stepS400 is a determination result that the acceleration suppression controloperation condition is established (“acceleration suppression controloperation condition is established?” in the figure) is performed.

In step S404, when it is determined that the determination result is thedetermination result that the acceleration suppression control operationcondition is established (“Yes” in the figure), the process performed bythe acceleration suppression instruction value calculation unit 10Jprogresses to step S406.

On the other hand, when it is determined that the determination resultis the determination result that the acceleration suppression controloperation condition is not established (“No” in the figure) in stepS404, the process performed by the acceleration suppression instructionvalue calculation unit 10J progresses to step S408.

In step S406, a process of calculating an acceleration suppressioninstruction value which is an acceleration instruction value forperforming the acceleration suppression control (“accelerationsuppression control instruction value calculation” in the figure) isperformed based on the information for calculating the accelerationsuppression instruction value acquired in step S402. After the processof calculating the acceleration suppression instruction value isperformed in step S406, the process performed by the accelerationsuppression instruction value calculation unit 10J progresses to stepS410.

Here, in the process of calculating the acceleration suppressioninstruction value, the depression amount of the accelerator pedal 32included in the driving-side depression amount signal, and theaccelerator suppression control amount included in the accelerationsuppression control amount signal are referenced. Further, anacceleration suppression control amount instruction value for settingthe opening degree of the throttle valve to a suppression degree (seeFIG. 14) depending on the acceleration suppression control amount withrespect to the actual opening degree of the accelerator pedal 32 iscalculated.

Further, in the process of calculating the acceleration suppressioninstruction value, the depression amount of the accelerator pedal 32included in the driving-side depression amount signal, and theacceleration suppression control start timing included in theacceleration suppression control start timing signal are referenced.Further, an acceleration suppression control start timing instructionvalue for setting the acceleration suppression control start timing as atiming (see FIG. 14) depending on the actual opening degree of theaccelerator pedal 32 is calculated.

In addition, in the process of calculating the acceleration suppressioninstruction value, an instruction value including the accelerationsuppression control amount instruction value and the accelerationsuppression control start timing instruction value calculated asdescribed above is calculated as the acceleration suppressioninstruction value.

In step S408, a process of calculating a normal acceleration instructionvalue which is an acceleration instruction value used in a driving forcecontrol in which the acceleration suppression control is not performed,that is, a normal acceleration control (“normal acceleration controlinstruction value calculation” in the figure), is performed. After theprocess of calculating the normal acceleration instruction value in stepS408 is performed, the process performed by the acceleration suppressioninstruction value calculation unit 10J progresses to step S412.

Here, in the process of calculating the normal acceleration instructionvalue, an instruction value for calculating the opening degree of thethrottle valve is calculated as the normal acceleration instructionvalue based on the depression amount of the accelerator pedal 32included in the driving-side depression amount signal.

In step S410, a process of outputting an acceleration suppressioninstruction value signal including the acceleration suppressioninstruction value calculated in step S406 to the target throttle valveopening degree calculation unit 10K (“acceleration suppressioninstruction value output” in the figure) is performed. After the processof outputting the acceleration suppression instruction value signal isperformed in step S410, the process performed by the accelerationsuppression instruction value calculation unit 10J is terminated (END).

In step S412, a process of outputting a normal acceleration instructionvalue signal including the normal acceleration instruction valuecalculated in step S408 to the target throttle valve opening degreecalculation unit 10K (“normal acceleration instruction value output” inthe figure) is performed. After the process of outputting the normalacceleration instruction value signal is performed in step S412, theprocess performed by the acceleration suppression instruction valuecalculation unit 10J is terminated (END).

(Process Performed by the Target Throttle Valve Opening DegreeCalculation Unit 10K)

Next, the process of the target throttle valve opening degreecalculation unit 10K will be described with reference to FIG. 16, whilereferring to FIG. 1 to FIG. 15. FIG. 16 is a flowchart illustrating theprocess performed by the target throttle valve opening degreecalculation unit 10K. The target throttle valve opening degreecalculation unit 10K performs the following process for eachpredetermined sampling time (for example, 10 msec).

As illustrated in FIG. 16, if the target throttle valve opening degreecalculation unit 10K starts the process (START), first, in step S500,the driving-side depression amount signal received from the acceleratoroperation amount calculation unit 10G is referenced. Further, a processof acquiring the depression amount (operation amount) of the acceleratorpedal 32 included in the driving-side depression amount signal(“accelerator operation amount acquisition process” in the figure) isperformed. After the process of acquiring the depression amount(operation amount) of the accelerator pedal 32 is performed in stepS500, the process performed by the target throttle valve opening degreecalculation unit 10K progresses to step S502.

In step S502, a process of acquiring the acceleration suppressioninstruction value (see step S406) or the normal acceleration instructionvalue (see step S408) (“instruction value acquisition process” in thefigure) is performed based on the information signal received from theacceleration suppression instruction value calculation unit 10J. Afterthe process of acquiring the acceleration suppression instruction valueor the normal acceleration instruction value is performed in step S502,the process performed by the target throttle valve opening degreecalculation unit 10K progresses to step S504.

In step S504, a process of calculating the opening degree of the targetthrottle valve (“target throttle valve opening degree calculation” inthe figure) is performed based on the depression amount of theaccelerator pedal 32 acquired in step S500 and the instruction valueacquired in step S502. After the opening degree of the target throttlevalve is calculated in step S504, the process performed by the targetthrottle valve opening degree calculation unit 10K progresses to stepS506.

Here, in step S504, when the instruction value acquired in step S502 isthe normal acceleration instruction value (when the accelerationsuppression operation condition is not established), the opening degreeof the throttle valve depending on the depression amount of theaccelerator pedal 32 is calculated as the opening degree of the targetthrottle valve.

On the other hand, when the instruction value acquired in step S502 isthe acceleration suppression instruction value (when the accelerationsuppression operation condition is established), the opening degree ofthe throttle valve depending on the acceleration suppression controlamount instruction value is calculated as the opening degree of thetarget throttle valve.

The opening degree of the target throttle valve is calculated using thefollowing Expression (1), for example.θ*=θ1−Δθ  (1)

In Expression (1), the opening degree of the target throttle valve isrepresented as “θ*”, the opening degree of the throttle valve dependingon the depression amount of the accelerator pedal 32 is represented as“θ1”, and the acceleration suppression control amount is represented as“Δθ”.

In step S506, the target throttle valve opening degree signal includingthe opening degree θ* of the target throttle valve calculated in stepS504 is output to the engine controller 12 (“target throttle valveopening degree output” in the figure). After the process of outputtingthe target throttle valve opening degree signal to the engine controller12 is performed in step S506, the process performed by the targetthrottle valve opening degree calculation unit 10K is terminated (END).

Here, in step S506, when the instruction value acquired in step S502 isthe acceleration suppression instruction value, the target throttlevalve opening degree signal is output at a timing when the openingdegree (depression amount) of the accelerator pedal 32 reaches theopening degree depending on the acceleration suppression control starttiming.

(Operation)

Next, an example of the process performed using the vehicle accelerationsuppression device 1 of the present embodiment will be described withreference to FIG. 1 to FIG. 16. In the example of the operationdescribed below, an example in which the vehicle V that travels in aparking lot enters the parking frame L0 selected by the driver will bedescribed.

In a state where the vehicle speed of the vehicle V that travels in theparking lot is equal to or greater than the vehicle speed thresholdvalue 15 km/h, since the acceleration suppression control operationcondition is not established, the normal acceleration control in whichan acceleration intention of the driver is reflected is performed in thevehicle V, without operating the acceleration suppression control.

When the vehicle speed is less than the vehicle speed threshold value,the parking frame L0 is detected, the brake pedal 30 is not operated,and the depression amount of the accelerator pedal 32 is equal to orgreater than the accelerator operation amount threshold value, it isdetermined whether or not the vehicle V enters the parking frame L0.

Further, during traveling of the vehicle V, the parking frame certaintydegree calculation unit 36 calculates the parking frame certaintydegree, and the parking frame entering certainty degree calculation unit38 calculates the parking frame entering certainty degree. Further, thetotal certainty degree calculation unit 40 calculates the totalcertainty degree based on the parking frame certainty degree and theparking frame entering certainty degree.

Further, during traveling of the vehicle V, the acceleration suppressioncontrol start timing calculation unit 42 calculates the accelerationsuppression control start timing, and the acceleration suppressioncontrol amount calculation unit 44 calculates the accelerationsuppression control amount, based on the total certainty degreecalculated by the total certainty degree calculation unit 40.

Further, if it is determined that the vehicle V enters the parking frameL0 and it is determined that the acceleration suppression controloperation condition is established, the acceleration suppressioninstruction value calculation unit 10J outputs the accelerationsuppression instruction value signal to the target throttle valveopening degree calculation unit 10K. Further, the target throttle valveopening degree calculation unit 10K outputs the target throttle valveopening degree signal to the engine controller 12.

Thus, if the driver operates the accelerator pedal 32 in a state wherethe acceleration suppression control operation condition is established,the opening degree of the throttle valve depending on the depressionamount of the accelerator pedal 32 is suppressed to the opening degreedepending on the acceleration suppression control amount instructionvalue. In addition, a starting timing when the opening degree of thethrottle valve depending on the depression amount of the acceleratorpedal 32 is suppressed is set to a timing depending on the accelerationsuppression control start timing instruction value.

Accordingly, in a situation where a braking operation is an appropriatedriving operation, for example, in a state where the vehicle Vapproaches a position suitable for parking in the parking frame L0, eventhough the accelerator pedal 32 is operated due to an operational erroror the like, it is possible to suppress the opening degree of thethrottle valve according to the total certainty degree. That is, in astate where the total certainty degree is low, since the accelerationsuppression amount (suppression degree of opening degree of a throttlevalve) is small, it is possible to reduce deterioration of operability,and in a state where the total certainty degree is high, since theacceleration suppression amount is large, it is possible to increase theacceleration suppression effect of the vehicle V.

As described above, in the present embodiment, in parking the vehicle,it is possible to suppress deterioration of operability in the parkinglot before the vehicle V enters the parking frame L0, and to suppressacceleration of the vehicle V due to the operational error of theaccelerator pedal 32.

Further, in the present embodiment, as the total certainty degreeincreases, the acceleration suppression control amount increases. Thus,the acceleration of the vehicle V is suppressed to enhance safety.Further, as the total certainty degree decreases, the accelerationsuppression control start timing is delayed to suppress deterioration ofoperability. Thus, under the following situations, it is possible toenhance safety and suppress deterioration of operability.

For example, in a situation where the vehicle V waiting in the vicinityof a place where the parking frame L0 for parallel parking is markedbeside a travel lane on a road starts movement, it is necessary to allowa certain degree of acceleration.

Further, in the following situation, it is also necessary to allow acertain degree of acceleration. This is a state where other vehicles arepresent on both sides (right and left parking frames) of the parkingframe L0 where the vehicle V is to be parked, the vehicle V enters somespace on an opposite side (side separated from each parking frame) fromthe front side thereof, and then, the vehicle V enters the parking frameL0 where the vehicle V is to be parked from the rear side thereof toperform parking.

In these situations, by controlling the acceleration suppression controlstart timing and the acceleration suppression control amount based onthe total certainty degree, it is possible to suppress the accelerationof the vehicle V to enhance safety. In addition, by allowing theacceleration of the vehicle V, it is possible to suppress deteriorationof operability.

Further, in the present embodiment, when the parking frame certaintydegree is low, the acceleration suppression control amount is calculatedto be smaller than a case where the parking frame certainty degree ishigh. Thus, as described below, in a situation where a current positionof the vehicle V is a position (for example, parking lot) which is not apublic road, it is possible to suppress deterioration of operability.

In a situation where the current position of the vehicle V is theposition which is not the public road, for example, a line in the imagecaptured by the peripheral environment recognition sensor 14 isdetected, but when the detected line cannot be specified as the parkingframe line, the parking frame certainty degree is calculated as a lowlevel. The case where the detected line cannot be specified as theparking frame line refers to a case where one line in the image capturedby the peripheral environment recognition sensor 14 is detected and anend portion thereof is detected but a line is not detected on a frontside (side close to the vehicle V) of the one detected line, forexample.

Further, for example, when the line detected in the image captured bythe peripheral environment recognition sensor 14 is a line of which anedge is blurred or a line which is blurred and is unclear, it isdetermined that the current position of the vehicle V is the positionwhich is not the public road, and the parking frame certainty degree iscalculated as a low level. This is because in many cases a line markedon a public road is generally regularly maintained by a publicorganization or the like, and thus, it may be estimated that a periodwhen the edge is blurred or the line is blurred and is unclear is short.

The above-described acceleration suppression instruction valuecalculation unit 10J and target throttle valve opening degreecalculation unit 10K correspond to an acceleration controller. Further,the above-described peripheral environment recognition informationcalculation unit 10A corresponds to a peripheral environment recognizer.

Further, the above-described vehicle speed calculation unit 10B,steering angle calculation unit 10C, steering angle speed calculationunit 10D, brake pedal operation information calculation unit 10F,accelerator operation amount calculation unit 10G, and acceleratoroperation speed calculation unit 10H correspond to a vehicle travelstate detector.

Further, the above-described acceleration suppression control starttiming calculation unit 42, acceleration suppression control amountcalculation unit 44, acceleration suppression instruction valuecalculation unit 10J, and target throttle valve opening degreecalculation unit 10K correspond to an acceleration controller. Further,the above-described opening degree of the throttle valve corresponds tothe acceleration instruction value.

In addition, the above-described navigation unit 26 corresponds to avehicle current position detector and a vehicle travel lane typedetector.

As described above, when the parking frame entering certainty degree islow, the vehicle acceleration suppression method executed by theoperation of the vehicle acceleration suppression device 1 of thepresent embodiment is a method for suppressing the accelerationinstruction value depending on the operation amount of the acceleratorpedal 32 with a low suppression degree, as compared with a case wherethe parking frame entering certainty degree is high. Here, the parkingframe entering certainty degree represents the degree of certainty thatthe vehicle V enters the parking frame L0, and is set based on theperipheral environment of the vehicle V and the travel state of thevehicle V.

Further, as described above, when the total certainty degree is low, thevehicle acceleration suppression method executed by the operation of thevehicle acceleration suppression device 1 of the present embodiment is amethod for suppressing the acceleration instruction value depending onthe operation amount of the accelerator pedal 32 with a low suppressiondegree, as compared with a case where the total certainty degree ishigh. Here, the total certainty degree represents a total certaintydegree of the parking frame certainty degree and the parking frameentering certainty degree. Further, the parking frame certainty degreerepresents the degree of certainty that the parking frame L0 is presentin a travel direction of the vehicle V, and is set based on theperipheral environment of the vehicle V.

Effects of First Embodiment

According to the present embodiment, the following effects can beachieved.

(1) The parking frame entering certainty degree calculation unit 38 isconfigured to calculate the parking frame entering certainty degreebased on the peripheral overlooking image (environment) of the vehicleV, the vehicle speed of the vehicle V, and the rotation angle (travelstate) of the steering wheel 28. In addition, when the parking frameentering certainty degree calculated by the parking frame enteringcertainty degree calculation unit 38 is low, the suppression degree ofthe acceleration instruction value becomes lower than a case where theparking frame entering certainty degree is high. That is, when theparking frame entering certainty degree calculated by the parking frameentering certainty degree calculation unit 38 is high, the suppressiondegree of the acceleration instruction value becomes higher than a casewhere the parking frame entering certainty degree is low. Thus, in astate where the parking frame entering certainty degree is low, it ispossible to reduce deterioration of operability by decreasing thesuppression degree of the acceleration instruction value, and in a statewhere the parking frame entering certainty degree is high, it ispossible to enhance the acceleration suppression effect of the vehicle Vby increasing the suppression degree of the acceleration instructionvalue. As a result, it is possible to suppress deterioration ofoperability of the vehicle V in parking the vehicle, and to suppressacceleration of the vehicle V due to an operational error of theaccelerator pedal 32.(2) The parking frame certainty degree calculation unit 36 is configuredto calculate the parking frame certainty degree based on the peripheraloverlooking image (environment) of the vehicle V and the vehicle speed(travel state) of the vehicle V. In addition, the total certainty degreecalculation unit 40 is configured to calculate the total certaintydegree based on the parking frame certainty degree calculated by theparking frame certainty degree calculation unit 36 and the parking frameentering certainty degree calculated by the parking frame enteringcertainty degree calculation unit 38. Further, when the total certaintydegree calculated by the total certainty degree calculation unit 40 islow, the suppression degree of the acceleration instruction valuebecomes lower than a case where the total certainty degree is high.Thus, in addition to the degree of certainty that the vehicle V entersthe parking frame L0, it is possible to control the suppression degreeof the acceleration instruction value according to the degree ofcertainty that the parking frame L0 is present in the travel directionof the vehicle V. As a result, in addition to the above-describedeffects (1), it is possible to suppress deterioration of operability ofthe vehicle V in parking the vehicle, and to suppress acceleration ofthe vehicle V due to an operational error of the accelerator pedal 32.(3) The acceleration suppression control start timing calculation unit42, the acceleration suppression instruction value calculation unit 10J,and the target throttle valve opening degree calculation unit 10K areconfigured to make the acceleration suppression control start timingearlier to increase the suppression degree of the accelerationinstruction value. As a result, it is possible to control the starttiming for suppressing the opening degree of the throttle valvedepending on the depression amount of the accelerator pedal 32, and tocontrol the suppression degree of the acceleration instruction value.(4) The acceleration suppression control amount calculation unit 44, theacceleration suppression instruction value calculation unit 10J, and thetarget throttle valve opening degree calculation unit 10K are configuredto increase the acceleration suppression control amount to increase thesuppression degree of the acceleration instruction value. As a result,it is possible to control the suppression amount of the opening degreeof the throttle valve depending on the depression amount of theaccelerator pedal 32, and to control the suppression degree of theacceleration instruction value.(5) In the vehicle acceleration suppression method of the presentembodiment, the parking frame entering certainty degree is calculatedbased on the peripheral overlooking image (environment) of the vehicle Vand the vehicle speed (travel state) of the vehicle V. In addition, whenthe parking frame entering certainty degree is low, if it is detectedthat the vehicle V enters the parking frame L0, the accelerationinstruction value is suppressed with a lower suppression degree than acase where the parking frame entering certainty degree is high. Thus, ina state where the parking frame entering certainty degree is low, it ispossible to reduce deterioration of operability by decreasing thesuppression degree of the acceleration instruction value, and in a statewhere the parking frame entering certainty degree is high, it ispossible to enhance the acceleration suppression effect of the vehicle Vby increasing the suppression degree of the acceleration instructionvalue. As a result, it is possible to suppress deterioration ofoperability of the vehicle V in parking the vehicle, and to suppressacceleration of the vehicle V due to an operational error of theaccelerator pedal 32.(6) In the vehicle acceleration suppression method of the presentembodiment, the parking frame certainty degree is calculated based onthe peripheral overlooking image (environment) of the vehicle V and thevehicle speed (travel state) of the vehicle V. In addition, the totalcertainty degree is calculated based on the calculated parking framecertainty degree and the parking frame entering certainty degree, andwhen the total certainty degree is low, the acceleration instructionvalue is suppressed with a lower suppression degree than a case wherethe total certainty degree is high. Thus, it is possible to control thesuppression degree of the acceleration instruction value according tothe degree of certainty that the vehicle V enters the parking frame L0and the degree of certainty that the parking frame L0 is present in thetravel direction of the vehicle V. As a result, in addition to theabove-described effect (5), it is possible to suppress deterioration ofoperability of the vehicle V in parking the vehicle, and to suppressacceleration of the vehicle V due to an operational error of theaccelerator pedal 32.

(Modifications)

(1) In the present embodiment, the acceleration suppression controlstart timing and the acceleration suppression control amount arecalculated based on the total certainty degree calculated by the totalcertainty degree calculation unit 40, but the present disclosure is notlimited thereto. That is, the acceleration suppression control starttiming and the acceleration suppression control amount may be calculatedbased on only the parking frame entering certainty degree calculated bythe parking frame entering certainty degree calculation unit 38. In thiscase, the acceleration suppression control start timing and theacceleration suppression control amount are calculated by making theparking frame entering certainty degree suitable for an accelerationsuppression condition calculation map illustrated in FIG. 17, forexample. FIG. 17 is a diagram illustrating a modification example of thepresent embodiment.(2) In the present embodiment, the parking frame certainty degreecalculation unit 36 is configured to calculate the parking framecertainty degree based on the peripheral overlooking image (environment)of the vehicle V and the vehicle speed (travel state) of the vehicle V,but the configuration of the parking frame certainty degree calculationunit 36 is not limited thereto. That is, the parking frame certaintydegree calculation unit 36 may be configured to calculate the parkingframe certainty degree using the current position of the vehicle Vincluded in the vehicle position signal, and the type (road type) of theroad on which the vehicle V travels included in the travel roadinformation signal, in addition to the peripheral overlooking image andthe vehicle speed of the vehicle V. In this case, for example, if it isdetected that the current position of the vehicle V is on a public roadbased on the information included in the position signal and the travelroad information signal, it is determined that the parking frame L0 isnot present in the vicinity of the vehicle V, and the parking framecertainty degree is calculated as “level 0”. Thus, for example, when thevehicle V enters a parking frame which is not preferable for theoperation of the acceleration suppression control, such as a parkingframe arranged on a road edge on the public road, it is possible tosuppress deterioration of operability of the vehicle V.(3) In the present embodiment, if it is determined that the end pointsface each other along the direction of the width WL with respect to theline La and Lb, the parking frame certainty degree calculation unit 36performs the process of calculating the parking frame certainty degreeas the level 3 or the level 4 (see step S212). However, the process ofcalculating the parking frame certainty degree as the level 3 or thelevel 4 is not limited thereto. That is, when it is recognized that theshape of the end point of the line L is a shape that is not marked onthe public road, such as a U-shape (see FIG. 4G to FIG. 4K, FIG. 4M, andFIG. 4N, for example), the parking frame certainty degree may becalculated as the level 3 or the level 4.(4) In the present embodiment, the parking frame certainty degreecalculation unit 36 is configured to calculate the parking framecertainty degree based on the peripheral overlooking image (environment)of the vehicle V and the vehicle speed (travel state) of the vehicle V,but the configuration of the parking frame certainty degree calculationunit 36 is not limited thereto. That is, in a configuration in which adevice (parking assist device) that assists the steering operation tothe parking frame L0 is provided for the driver, the vehicle V may havea configuration in which the level of the parking frame certainty degreeeasily increases when the parking assist device is in the ON state maybe used. Here, the configuration in which the level of the parking framecertainty degree easily increases refers to a configuration in which theabove-described setting moving distance is set to a distance shorterthan a normal distance, for example.

Further, as the parking assist device, for example, there is a devicethat displays on a monitor a peripheral situation using an overlookingimage or the like in order to perform parking, or a device that sets atarget parking position on a screen in order to guide a course forparking. Such a device is used by operating a switch that switches ascreen for monitor-displaying the peripheral situation using theoverlooking image or the like, or a switch that switches a screen forsetting the target parking position on the screen. Further, aconfiguration in which if the switch is operated so that the parkingassist device enters the ON state, detection of the paring frame iseasily performed so that the level of the parking frame certainty degreeeasily increases may be used.

Here, as a method for easily detecting the parking frame, for example,there is a method for correcting the setting value so that theconditions C1 to C4 of the above-described step S206 are established.Further, there is a method, other than the correction method, forsetting the setting moving distance used when it is determined in stepS206 that the continuous check state reaches the setting moving distanceto be short. In addition, for example, there is a method for setting thecondition of the end points when it is determined in step S212 that theparking frame certainty degree is the level 3 or the level 4 so that thenumber of the end points is smaller than the initial setting, forexample. As the method for easily detecting the parking frame, forexample, a method for detecting the parking frame certainty degree as aset level in advance (for example, “level 4”) regardless of the actualdetection situation of the parking frame may be used.

(5) In the present embodiment, the acceleration suppression controlamount and the acceleration suppression control start timing are changedbased on the total certainty degree to change the suppression degree ofthe acceleration instruction value, but the present disclosure is notlimited thereto. That is, only the acceleration suppression controlstart timing or only the acceleration suppression control amount ischanged according to the total certainty degree to change thesuppression degree of the acceleration instruction value. In this case,for example, as the total certainty degree increases, the accelerationsuppression control amount may be set to be large, and the accelerationsuppression control start timing may not be changed, so that thesuppression degree of the acceleration instruction value may increase.(6) In the present embodiment, the total certainty degree is calculatedbased on the calculated parking frame certainty degree and the parkingframe entering certainty degree regardless of the number of space linedetected when the level of the parking frame certainty degree iscalculated, but the present disclosure is not limited thereto. That is,for example, the total certainty degree may be calculated according tothe number of lines L detected when the above-described condition B issatisfied. In this case, for example, the number of lines L detectedwhen the condition B is satisfied in addition to the calculated parkingframe certainty degree and parking frame entering certainty degree ismade to be suitable for a total certainty degree calculation mapillustrated in FIG. 18. Further, the total certainty degree iscalculated based on the parking frame certainty degree and the parkingframe entering certainty degree, and the type of the line L detectedwhen the condition B is satisfied. FIG. 18 is a diagram illustrating thetotal certainty degree calculation map used in a modification example ofthe present embodiment. Further, in FIG. 18, similarly to FIG. 13, theparking frame certainty degree is represented as a “frame certaintydegree”, and the parking frame entering certainty degree is representedas an “entering certainty degree”.

In the above-described case, as illustrated in FIG. 18, when the parkingframe entering certainty degree is “low level” and the parking framecertainty degree is calculated as “level 1”, and when the parking frameentering certainty degree is “low level” and the parking frame certaintydegree is calculated as “level 2 to 4”, the total certainty degree iscalculated according to the type of the line L detected when thecondition B is satisfied.

Specifically, when the parking frame entering certainty degree is “lowlevel” and the parking frame certainty degree is calculated as “level1”, and when the type of the line L detected when the condition B issatisfied is a single line, the total certainty degree is calculated asa total certainty degree with which the acceleration suppression controlis not performed, similarly to the case of “level 0”. Further, when theparking frame entering certainty degree is “low level” and the parkingframe certainty degree is calculated as “level 1”, and when the type ofthe line L detected when the condition B is satisfied is a double line,the total certainty degree is calculated as “extremely low”.

When the parking frame entering certainty degree is “low level” and theparking frame certainty degree is calculated as “level 2 to 4”, and whenthe type of the line L detected when the condition B is satisfied is asingle line, the total certainty degree is calculated as “extremelylow”. Further, when the parking frame entering certainty degree is “lowlevel” and the parking frame certainty degree is calculated as “level 2to 4”, and when the type of the line L detected when the condition B issatisfied is a double line, the total certainty degree is calculated as“extremely high”.

Here, when the total certainty degree is calculated using the totalcertainty degree calculation map illustrated in FIG. 18, for example,the calculated total certainty degree is made to be suitable for anacceleration suppression condition calculation map illustrated in FIG.19 to calculate the acceleration suppression control start timing. FIG.19 is a diagram illustrating the acceleration suppression conditioncalculation map used in a modification example of the presentembodiment. Further, in FIG. 19, similarly to FIG. 14, in a unit of“acceleration suppression condition”, the acceleration suppressioncontrol start timing is represented as “suppression control start timing(opening degree of an accelerator pedal)”.

When calculating the acceleration suppression control start timing usingthe acceleration suppression condition calculation map illustrated inFIG. 19, when the total certainty degree is “extremely low”, timemeasurement of the acceleration suppression control start timing isstarted at a time point when the opening degree of the accelerator pedal32 increases to reach “80%”. In addition, a time point when themeasurement time when the opening degree of the accelerator pedal 32 isequal to or greater than “80%” reaches “0.25 sec” is set as theacceleration suppression control start timing. That is, when the totalcertainty degree is “extremely low”, the acceleration suppressioncontrol is started from the time point when the measurement time whenthe opening degree of the accelerator pedal 32 is equal to or greaterthan “80%” reaches “0.25 sec”.

Further, an acceleration suppression control amount when the totalcertainty degree is “extremely low” is set to be a control amount inwhich the opening degree of the throttle valve is suppressed to a“small” level. In FIG. 19, similarly to FIG. 14, in a unit of“acceleration suppression condition”, the acceleration suppressioncontrol amount is represented as a “suppression amount”.

On the other hand, when the total certainty degree is “extremely high”,the time measurement of the acceleration suppression control starttiming is started at a time point when the opening degree of theaccelerator pedal 32 increases to reach “50%”. In addition, a time pointwhen the measurement time when the opening degree of the acceleratorpedal 32 is equal to or greater than “50%” reaches “0.65 sec” is set asthe acceleration suppression control start timing. That is, when thetotal certainty degree is “extremely high”, the acceleration suppressioncontrol is started from the time point when the measurement time whenthe opening degree of the accelerator pedal 32 is equal to or greaterthan “50%” reaches “0.65 sec”.

Further, an acceleration suppression control amount when the totalcertainty degree is “extremely high” is set to be a control amount inwhich the opening degree of the throttle valve is suppressed to a “high”level.

Here, an operation example when the acceleration suppression controlstart timing is calculated using the acceleration suppression conditioncalculation map illustrated in FIG. 19 will be described.

When the acceleration suppression condition calculation map illustratedin FIG. 19 is used, the relationship between the accelerationsuppression control start timing based on the total certainty degree anda maintenance time becomes a relationship illustrated in FIG. 20. FIG.20 is a diagram illustrating the relationship between the accelerationsuppression control start timing and the maintenance time. Further, inFIG. 20, the acceleration suppression control start timing isrepresented as “acceleration opening degree %” on a transverse axis, andthe maintenance time is represented as “maintenance time (sec)” on alongitudinal axis.

As illustrated in FIG. 20, when the total certainty degree is calculatedas “extremely low”, a time point PL when the measurement time when theopening degree of the accelerator pedal is equal to or greater than 80%reaches “0.25 sec” is set as the acceleration suppression control starttiming. Further, when the total certainty degree is calculated as“extremely high”, a time point PH when the measurement time when theopening degree of the accelerator pedal is equal to or greater than 50%reaches “0.65 sec” is set as the acceleration suppression control starttiming. In FIG. 20, a line continuously indicating control thresholdvalues which serve as a setting reference of the accelerationsuppression control start timing is indicated by a solid line.

However, when the images captured by the peripheral environmentrecognition sensor 14 while the vehicle V is traveling are changed, thetype of the line L detected when the condition B is satisfied may bechanged.

Here, for example, in a situation where the parking frame certaintydegree is calculated as “level 2 to 4”, a case where the type of theline L detected when the condition B is satisfied is changed from asingle line to a double line may be considered.

In this case, at a time point when the type of the line L detected whenthe condition B is satisfied is changed from the single line to thedouble line, the total certainty degree is changed from “extremely low”to “extremely high”.

At a time point when the type of the line L detected when the conditionB is satisfied is the single line, the time point PL illustrated in FIG.20 is set as the acceleration suppression control start timing, and themeasurement of the maintenance time is not started until theacceleration opening degree reaches 80%.

However, if the total certainty degree is changed from “extremely low”to “extremely high”, even though the opening degree of the acceleratorpedal already reaches 50%, the measurement of the maintenance time isstarted from the time point when the total certainty degree is changedfrom “extremely low” to “extremely high”. Further, in FIG. 20, theacceleration suppression control is started from a time point SP whenthe relationship between the measurement time and the opening degree ofthe accelerator pedal overlaps the line continuously indicating thecontrol threshold values. In FIG. 20, the change in the opening degreeof the accelerator pedal depending on the lapse of time is indicated bya broken line.

Accordingly, when the total certainty degree is changed from “extremelylow” to “extremely high”, the time when the acceleration suppressioncontrol is started is delayed as compared with a case where the totalcertainty degree is calculated as “extremely high” from the beginning.

Thus, for example, in a situation where the vehicle V travels on arising slope when traveling a parking lot where plural parking framesare arranged, such as a parking tower to move to an upper floor parkinglot from a lower floor parking lot, it is possible to suppressdeterioration of operability. This is applied to a situation where thestraight travel is changed to the turning travel before the vehicle Vtravels on the rising slope to decrease the vehicle speed, and the typeof the line L detected when the condition B is satisfied is changed fromthe single line to the double line, so that the total certainty degreeis changed from “extremely low” to “extremely high”.

In this situation, even though the straight travel is changed to theturning travel before the vehicle V travels on the rising slope todecrease the vehicle speed and the total certainty degree is changedfrom “extremely low” to “extremely high”, the time when the accelerationsuppression control is started is delayed as compared with a case wherethe total certainty degree is calculated as “extremely high” from thebeginning. Thus, as compared with a case where the total certaintydegree is calculated as “extremely high” from the beginning, the timingwhen the acceleration suppression control is started is delayed toincrease a possibility that the parking frame certainty degree iscalculated as “level 0”, and a time point when the vehicle travels onthe rising slope is used as a time point when the accelerationsuppression control is started.

Next, for example, in a situation where the parking frame certaintydegree is calculated as “level 2 to 4”, a case where the type of theline L detected when the condition B is satisfied is the single line andthe parking frame entering certainty degree is changed from “low level”to “high level” may be considered.

In this case, at a time point when the parking frame entering certaintydegree is changed from “low level” to “high level”, the total certaintydegree is changed from “extremely low” to “extremely high”. Further,similarly to a case where the type of the line L detected when thecondition B is satisfied is changed from the single line to the doubleline, the time when the acceleration suppression control is started isdelayed as compared with a case where the total certainty degree iscalculated as “extremely high” from the beginning.

Thus, for example, in a situation where the vehicle V turns left at anintersection after left turn, overtakes another vehicle which is avehicle that is already parked, and then, enters a parking framedisposed at a road edge for parking, it is possible to reducedeterioration of operability. This is applied to a situation where whenthe vehicle V turns left at an intersection, overtakes another vehiclefrom a right side, and then moves left toward a road edge, the parkingframe entering certainty degree is changed from “low level” to “highlevel”, and the total certainty degree is changed from “extremely low”to “extremely high”.

In this situation, when the vehicle speed decreased due to the left turnat the intersection is increased, even though the total certainty degreeis changed from “extremely low” to “extremely high”, the time when theacceleration suppression control is started is delayed as compared witha case where the total certainty degree is calculated as “extremelyhigh” from the beginning”. Thus, as compared with a case where the totalcertainty degree is calculated as “extremely high” from the beginning,the timing when the acceleration suppression control is started isdelayed to increase a possibility that the vehicle speed is deceleratedon a public road, and a time point when the parking is started duringtraveling is used as the time point when the acceleration suppressioncontrol is started.

(7) In the present embodiment, the acceleration of the vehicle Vdepending on the depression amount (driving force operation amount) ofthe accelerator pedal 32 is suppressed by controlling the accelerationinstruction value, but the present disclosure is not limited thereto.That is, for example, the acceleration of the vehicle V depending on thedriving force operation amount may be suppressed by setting the openingdegree of the throttle valve depending on the depression amount (drivingforce operation amount) of the accelerator pedal 32 as an opening degreeof a target throttle valve and generating a braking force by theabove-described brake system.(8) In the present embodiment, the parking frame certainty degree iscalculated as the level 0 which is the lowest value and the levels(level 1 to level 4) which are higher than the lowest value by pluralsteps, but the steps of the parking frame certainty degree are notlimited thereto. That is, the parking frame certainty degree may becalculated as only two steps of a level (for example, “level 0”) whichis the lowest value and a level (for example, “level 100”) which ishigher than the lowest value.(9) In the present embodiment, the parking frame entering certaintydegree is calculated as “level 0” which is the lowest value, “low level”which is the level higher than the level 0, and “high level” which isthe level higher than the low level, but the steps of the parking frameentering certainty degree are not limited thereto. That is, the parkingframe entering certainty degree may be calculated as only two steps of alevel which is the lowest value (for example, “level 0”) and a levelwhich is higher than the lowest value (for example, “level 100”).(10) In the present embodiment, the total certainty degree is calculatedas any one of the four-step levels (“extremely low”, “low”, “high”, and“extremely high”) according to the parking frame certainty degreecalculated as any one of the five-step levels and the parking frameentering certainty degree calculated as any one of the three-steplevels. However, the steps of the total certainty degree are not limitedthereto. That is, the total certainty degree may be calculated as onlytwo steps of a level (for example, “level 0”) which is the lowest valueand a level which is higher than the lowest value (for example, “level100”). In this case, for example, when the parking frame certaintydegree and the parking frame entering certainty degree are calculated asthe level which is the lowest value, the total certainty degree iscalculated as the level which is the lowest value. Further, for example,when the parking frame certainty degree and the parking frame enteringcertainty degree are calculated as the level which is higher than thelowest value, the total certainty degree is calculated as the levelwhich is higher than the lowest value.

Second Embodiment

Hereinafter, a second embodiment of the disclosure (hereinafter,referred to as “the present embodiment”) will be described withreference to the accompanying drawings.

(Configuration)

First, the configuration of a vehicle acceleration suppression device 1of the present embodiment will be described with reference to FIG. 21and FIG. 22, while referring to FIG. 1 to FIG. 20. Since a vehicleacceleration suppression device 1 of the present embodiment is the sameas the above-described first embodiment except for a process performedby the acceleration suppression control content calculation unit 10I,repetitive description may be omitted with respect to processes otherthan the process performed by the acceleration suppression controlcontent calculation unit 10I.

Further, the vehicle acceleration suppression device 1 of the presentembodiment is different from the above-described first embodiment inprocesses other than a process performed by the acceleration suppressionoperation condition determination unit 34 in the process performed bythe acceleration suppression control content calculation unit 10I. Thus,in the following description, the same processes as those of theabove-described first embodiment may not be described.

In the above-described process of step S208, the parking frame certaintydegree calculation unit 36 of the present embodiment first determineswhether or not the travel direction of the vehicle V is an advancingdirection or a retreating direction, and sets a setting moving distanceaccording to the determination result. Further, the parking framecertainty degree calculation unit 36 performs a process of determiningwhether or not the process of step S206 is continuously checked untilthe moving distance of the vehicle V reaches the setting moving distanceafter the process of step S206 is started, based on the setting movingdistance set according to the travel direction of the vehicle V.

Here, the process of setting the setting moving distance according tothe travel direction of the vehicle V is performed with reference to acurrent shift position signal received from the shift positioncalculation unit 10E, for example.

Further, in the present embodiment, for example, a case where thesetting moving distance is set to 2.5 m when it is determined that thetravel direction of the vehicle V is the advancing direction and is setto 1 m when it is determined that the travel direction of the vehicle Vis the retreating direction will be described.

The setting moving distance is exemplary, and for example, may bechanged according to specification of the vehicle V, such as brakingperformance of the vehicle V. Further, for example, the setting movingdistance may be changed according to a traffic law or the like of aplace (nation or the like) where the vehicle V is traveling.

Accordingly, in the present embodiment, in the process of step S208,when the travel direction of the vehicle V is the advancing direction,the level of the parking frame certainty degree is not easily calculatedas “level 1”, when compared with a case where the travel direction ofthe vehicle V is the retreating direction.

Further, the parking frame certainty degree calculation unit 36 of thepresent embodiment determines whether or not the travel direction of thevehicle V is the advancing direction or the retreating direction in theabove-described process of step S212.

Further, when the travel direction of the vehicle V is the advancingdirection, similarly to the above-described first embodiment, when it isdetermined that the end points positioned at the same side face eachother along the direction of the width WL, the process performed by theparking frame certainty degree calculation unit 36 progresses to stepS216.

On the other hand, when the travel direction of the vehicle V is theretreating direction, when it is recognized that the shape of the endpoint of one of the lines La and Lb is a U-shape (see FIG. 4G to FIG.4K, FIG. 4M, and FIG. 4N, for example), the process performed by theparking frame certainty degree calculation unit 36 progresses to stepS216. That is, when the travel direction of the vehicle V is theretreating direction, when it is recognized that the shape of the endpoint of one of the lines La and Lb is a shape that is not marked on apublic road, the process performed by the parking frame certainty degreecalculation unit 36 progresses to step S216.

Accordingly, in the present embodiment, in the process of step S212,when the travel direction of the vehicle V is the advancing direction,the level of the parking frame certainty degree is not easily calculatedas “level 3”, as compared with a case where the travel direction of thevehicle V is the retreating direction.

That is, in the present embodiment, when the travel direction of thevehicle V is the advancing direction, the level of the parking framecertainty degree does not easily increase, as compared with a case wherethe travel direction of the vehicle V is the retreating direction. Thus,in the present embodiment, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

Further, the parking frame entering certainty degree calculation unit 38of the present embodiment first determines whether or not the traveldirection of the vehicle V is the advancing direction or the retreatingdirection, in the above-described process of step S314.

Then, when the travel direction of the vehicle V is the advancingdirection, a process of calculating the parking frame entering certaintydegree as a low level during advancing is performed, and when the traveldirection of the vehicle V is the retreating direction, a process ofcalculating the parking frame entering certainty degree as a low levelduring retreating is performed.

Further, the parking frame entering certainty degree calculation unit 38first determines whether or not the travel direction of the vehicle V isthe advancing direction or the retreating direction, in theabove-described process of step S316.

Then, when the travel direction of the vehicle V is the advancingdirection, a process of calculating the parking frame entering certaintydegree as a high level during advancing is performed, and when thetravel direction of the vehicle V is the retreating direction, a processof calculating the parking frame entering certainty degree as a highlevel during retreating is performed.

Further, a total certainty degree calculation unit 40 of the presentembodiment receives an input of the parking frame certainty degreesignal and the parking frame entering certainty degree signal, and makesthe parking frame certainty degree included in the parking framecertainty degree signal and the parking frame entering certainty degreeincluded in the parking frame entering certainty degree signal suitablefor a total certainty degree calculation map illustrated in FIG. 21.Further, the total certainty degree calculation unit 40 calculates thetotal certainty degree based on the parking frame certainty degree andthe parking frame entering certainty degree.

FIG. 21 is a diagram illustrating the total certainty degree calculationmap used in the present embodiment. In FIG. 21, similarly to FIG. 13,the parking frame certainty degree is represented as a “frame certaintydegree”, and the parking frame entering certainty degree is representedas an “entering certainty degree”.

Here, the total certainty degree calculation map used by the totalcertainty degree calculation unit 40 of the present embodiment isdifferent from the total certainty degree calculation map used by thetotal certainty degree calculation unit 40 of the above-described firstembodiment, in which the level of the total certainty degree is changedaccording to the determination result of the travel direction of thevehicle V. In FIG. 21, the total certainty degree when it is determinedthat the travel direction of the vehicle V is the advancing direction isrepresented as “low advance level” and “high advance level” in a unit of“entering certainty degree”. In addition, in FIG. 21, the totalcertainty degree when it is determined that the travel direction of thevehicle V is the retreating direction is represented as “low retreatlevel” and “high retreat level” in a unit of “entering certaintydegree”.

The “low advance level” corresponds to the process of calculating theparking frame entering certainty degree as the low level duringadvancing in the above-described process of step S314. Further, the “lowretreat level” corresponds to the process of calculating the parkingframe entering certainty degree as the low level during retreating inthe above-described process of step S314.

Similarly, the “high advance level” corresponds to the process ofcalculating the parking frame entering certainty degree as the highlevel during advancing in the above-described process of step S316.Further, the “high retreat level” corresponds to the process ofcalculating the parking frame entering certainty degree as the highlevel during retreating in the above-described process of step S316.

Further, the total certainty degree calculation unit 40 of the presentembodiment calculates the total certainty degree when it is determinedthat the travel direction of the vehicle V is the retreating directionas a level which is equal to or higher than that of the total certaintydegree when it is determined that the travel direction of the vehicle Vis the advancing direction as illustrated in FIG. 21.

As an example of the process of calculating the total certainty degreeby the total certainty degree calculation unit 40 of the presentembodiment, when the parking frame certainty degree is “level 2” and theparking frame entering certainty degree is “high advance level”, asillustrated in FIG. 21, the total certainty degree is calculated as“low”. On the other hand, when the parking frame certainty degree is“level 2” and the parking frame entering certainty degree is “highretreat level”, as illustrated in FIG. 21, the total certainty degree iscalculated as “high”.

Further, as an example of the process of calculating the total certaintydegree by the total certainty degree calculation unit 40 of the presentembodiment, a process of easily increasing the level of the parkingframe certainty degree before advancing by considering that the vehicleV is already being parked even though the travel direction of thevehicle V is the advancing direction and by performing the samecalculation as in retreating may be performed. This process is appliedto a case where the vehicle V retreats after the parking frame certaintydegree is calculated as “level 1” during advancing of the vehicle V andadvances again during retreating within a predetermined distance (forexample, 2.5 m).

As described above, in the present embodiment, when the travel directionof the vehicle V is the advancing direction, the level of the totalcertainty degree does not easily increase, as compared with a case wherethe travel direction of the vehicle V is the retreating direction. Thus,in the present embodiment, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

Further, when it is determined that the travel direction of the vehicleV is the retreating direction, the acceleration suppression controlstart timing calculation unit 42 of the present embodiment makes thetotal certainty degree included in the total certainty degree signalsuitable for a retreat acceleration suppression condition calculationmap illustrated in FIG. 22. Further, the acceleration suppressioncontrol start timing calculation unit 42 calculates the accelerationsuppression control start timing based on the total certainty degree.

FIG. 22 is a diagram illustrating the retreat acceleration suppressioncondition calculation map. Further, in FIG. 22, similarly to FIG. 14,the acceleration suppression control start timing is represented as“suppression control start timing (acceleration opening degree)” in aunit of “acceleration suppression condition”.

Here, in the retreat acceleration suppression condition calculation mapused by the acceleration suppression control start timing calculationunit 42 of the present embodiment, the acceleration suppression controlstart timing with respect to the total certainty degree is set to beearlier than the acceleration suppression condition calculation map ofthe above-described first embodiment. Accordingly, in the retreatacceleration suppression condition calculation map used by theacceleration suppression control start timing calculation unit 42 of thepresent embodiment, when the travel direction of the vehicle V is theretreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

As an example of the process performed by the acceleration suppressioncontrol start timing calculation unit 42 of the present embodiment, whenthe total certainty degree is “low”, as illustrated in FIG. 22, theacceleration suppression control start timing is set to a timing whenthe opening degree of the accelerator pedal 32 increases to reach “50%”.The acceleration suppression control start timing illustrated in FIG. 22is exemplary, and may be changed according to specification or the likeof the vehicle V, similarly to the acceleration suppression controlstart timing illustrated in FIG. 14.

Further, when it is determined that the travel direction of the vehicleV is the retreating direction, the acceleration suppression controlamount calculation unit 44 of the present embodiment makes the totalcertainty degree included in the total certainty degree signal suitablefor the retreat acceleration suppression condition calculation mapillustrated in FIG. 22. Further, the acceleration suppression controlamount calculation unit 44 calculates the acceleration suppressioncontrol amount based on the total certainty degree. In FIG. 22, theacceleration suppression control amount is represented as “suppressionamount” in a unit of “acceleration suppression condition”, similarly toFIG. 14.

Here, in retreat acceleration suppression condition calculation map usedby the acceleration suppression control amount calculation unit 44, theacceleration suppression control amount with respect to the totalcertainty degree is set to be large, as compared with the accelerationsuppression condition calculation map of the above-described firstembodiment. Accordingly, in the retreat acceleration suppressioncondition calculation map used by the acceleration suppression controlamount calculation unit 44 of the present embodiment, when the traveldirection of the vehicle V is the retreating direction, the suppressiondegree of the acceleration instruction value increases, as compared witha case where the travel direction of the vehicle V is the advancingdirection.

As an example of the process performed by the acceleration suppressioncontrol amount calculation unit 44 of the present embodiment, when thetotal certainty degree is “extremely low”, as illustrated in FIG. 22,the acceleration suppression control amount is set as a control amountin which an actual opening degree of the accelerator pedal 32 issuppressed to an opening degree of a throttle valve of a “medium” level.The acceleration suppression control amount illustrated in FIG. 22 isexemplary, and may be changed according to specification or the like ofthe vehicle V, similarly to the acceleration suppression control amountillustrated in FIG. 14.

As described above, in the present embodiment, when the travel directionof the vehicle V is the advancing direction, as compared with a casewhere the travel direction of the vehicle V is the retreating direction,the acceleration suppression control start timing is set to be earlier,and the acceleration suppression control amount is set to be larger.Thus, in the present embodiment, when the travel direction of thevehicle V is the retreating direction, as compared with a case where thetravel direction of the vehicle V is the advancing direction, thesuppression degree of the acceleration instruction value increases.

(Operation)

Next, an example of the operation performed using the vehicleacceleration suppression device 1 of the present embodiment will bedescribed with reference to FIG. 1 to FIG. 22. With respect to the sameoperation or the like as that of the above-described first embodiment,repetitive description may be omitted.

In the example of the operation described below, similarly to theabove-described first embodiment, an example in which the vehicle V thattravels in a parking lot enters a parking frame L0 selected by a driverwill be described.

While the vehicle V is traveling, the parking frame certainty degreecalculation unit 36 calculates the parking frame certainty degree, andthe parking frame entering certainty degree calculation unit 38calculates the parking frame entering certainty degree. Further, thetotal certainty degree calculation unit 40 calculates the totalcertainty degree based on the parking frame certainty degree and theparking frame entering certainty degree.

Further, while the vehicle V is traveling, the acceleration suppressioncontrol start timing calculation unit 42 calculates the accelerationsuppression control start timing, and the acceleration suppressioncontrol amount calculation unit 44 calculates the accelerationsuppression control amount, based on the total certainty degreecalculated by the total certainty degree calculation unit 40.

Further, when it is determined that the vehicle V enters the parkingframe L0 and it is determined that the acceleration suppression controloperation condition is established, the acceleration suppressioninstruction value calculation unit 10J outputs the accelerationsuppression instruction value signal to the target throttle valveopening degree calculation unit 10K. Further, the target throttle valveopening degree calculation unit 10K outputs the target throttle valveopening degree signal to the engine controller 12.

Here, in the present embodiment, in the process of calculating theparking frame certainty degree by the parking frame certainty degreecalculation unit 36, when the travel direction of the vehicle V is theadvancing direction, the level of the parking frame certainty degreedoes not easily increase, as compared with a case where the traveldirection of the vehicle V is the retreating direction.

Thus, in a state where the acceleration suppression control operationcondition is established, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

In addition, in the present embodiment, in the process of calculatingthe parking frame entering certainty degree by the parking frameentering certainty degree calculation unit 38, when the travel directionof the vehicle V is the advancing direction, the level of the parkingframe entering certainty degree does not easily increase, as comparedwith a case where the travel direction of the vehicle V is theretreating direction.

Thus, in a state where the acceleration suppression control operationcondition is established, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

In addition, in the present embodiment, in the process of calculatingthe total certainty degree by the total certainty degree calculationunit 40, when the travel direction of the vehicle V is the advancingdirection, the level of the parking frame certainty degree does noteasily increase, as compared with a case where the travel direction ofthe vehicle V is the retreating direction.

Thus, in a state where the acceleration suppression control operationcondition is established, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

Further, in the present embodiment, in the process of calculating theacceleration suppression control start timing by the accelerationsuppression control start timing calculation unit 42, when the traveldirection of the vehicle V is the advancing direction, the level of theparking frame certainty degree does not easily increase, as comparedwith a case where the travel direction of the vehicle V is theretreating direction.

Thus, in a state where the acceleration suppression control operationcondition is established, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

In addition, in the present embodiment, in the process of calculatingthe acceleration suppression control amount by the accelerationsuppression control amount calculation unit 44, when the traveldirection of the vehicle V is the advancing direction, the level of theparking frame certainty degree does not easily increase, as comparedwith a case where the travel direction of the vehicle V is theretreating direction.

Thus, in a state where the acceleration suppression control operationcondition is established, when the travel direction of the vehicle V isthe retreating direction, the suppression degree of the accelerationinstruction value increases, as compared with a case where the traveldirection of the vehicle V is the advancing direction.

The above-described shift position sensor 20 and shift positioncalculation unit 10E correspond to a vehicle travel direction detector.

Further, as described above, when the travel direction of the vehicle Vis the advancing direction, the vehicle acceleration suppression controlmethod of the present embodiment is a method for suppressing theacceleration instruction value depending on the operation amount of theaccelerator pedal 32 with a low suppression degree, as compared with acase where the travel direction of the vehicle V is the retreatingdirection.

Effects of Second Embodiment

Hereinafter, effects of the present embodiment will be described. In thepresent embodiment, the following effects can be achieved, in additionto the effects of the above-described first embodiment.

(1) The travel state of the vehicle is detected by the shift positionsensor 20 and the shift position calculation unit 10E. In addition, whenthe travel direction of the vehicle V is the advancing direction, theacceleration suppression control start timing calculation unit 42, theacceleration suppression control amount calculation unit 44, theacceleration suppression instruction value calculation unit 10J, and thetarget throttle valve opening degree calculation unit 10K decrease thesuppression degree of the acceleration instruction value, as comparedwith a case where the travel direction of the vehicle is the retreatingdirection. That is, when the travel direction of the vehicle V is theretreating direction, the acceleration suppression control start timingcalculation unit 42, the acceleration suppression control amountcalculation unit 44, the acceleration suppression instruction valuecalculation unit 10J, and the target throttle valve opening degreecalculation unit 10K increase the suppression degree of the accelerationinstruction value, as compared with a case where the travel direction ofthe vehicle V is the advancing direction. Thus, when the traveldirection of the vehicle V is the advancing direction in which thedriver easily views the travel direction, the suppression degree of theacceleration instruction value decreases as compared with a case wherethe travel direction of the vehicle V is the retreating direction inwhich the driver does not view more easily than the advancing direction,to thereby make it possible to reduce deterioration of operability.Further, when the travel direction of the vehicle V is the retreatingdirection in which the driver does not view more easily than theadvancing direction, the suppression degree of the accelerationinstruction value increases as compared with a case where the traveldirection of the vehicle V is the advancing direction where the drivereasily views the travel direction, to thereby make it possible toenhance the acceleration suppression effect of the vehicle V. As aresult, it is possible to suppress deterioration of operability of thevehicle V in parking the vehicle, and to suppress acceleration of thevehicle V due to an operational error of the accelerator pedal 32.(2) In the vehicle acceleration suppression control method of thepresent embodiment, the travel direction of the vehicle V is detected,and when the travel direction of the vehicle V is the advancingdirection, the acceleration instruction value is suppressed with a lowsuppression degree, as compared with a case where the travel directionof the vehicle V is the retreating direction. Thus, when the traveldirection of the vehicle V is the advancing direction where the drivereasily views the travel direction, the suppression degree of theacceleration instruction value decreases as compared with a case wherethe travel direction of the vehicle V is the retreating direction inwhich the driver does not view more easily the advancing direction, tothereby make it possible to reduce deterioration of operability.Further, when the travel direction of the vehicle V is the retreatingdirection in which the driver does not view more easily than theadvancing direction, the suppression degree of the accelerationinstruction value increases as compared with a case where the traveldirection of the vehicle V is the advancing direction where the drivereasily views the travel direction, to thereby make it possible toenhance the acceleration suppression effect of the vehicle V. As aresult, it is possible to suppress deterioration of operability of thevehicle V in parking the vehicle, and to suppress acceleration of thevehicle V due to an operational error of the accelerator pedal 32.

(Modifications)

(1) In the present embodiment, when the travel direction of the vehicleV is the advancing direction, the level of the parking frame certaintydegree does not easily increase as compared with a case where the traveldirection of the vehicle V is the retreating direction, so that thesuppression degree of the acceleration instruction value decreases, butthe present disclosure is not limited thereto. That is, for example,when the setting of at least one of the parallelism threshold value, theturning radius threshold value, the first threshold value, and thesecond threshold value may be changed, so that when the travel directionof the vehicle V is the advancing direction, the level of the parkingframe entering certainty degree may not easily increase, as comparedwith a case where the travel direction of the vehicle V is theretreating direction. Thus, when the travel direction of the vehicle Vis the advancing direction, the level of the parking frame enteringcertainty degree does not easily increase, as compared with a case wherethe travel direction of the vehicle V is the retreating direction, sothat the suppression degree of the acceleration instruction valuedecreases.(2) In the present embodiment, when the travel direction of the vehicleV is the advancing direction, the setting moving distance is set to belonger than a case where the travel direction of the vehicle V is theretreating direction, so that the level of the parking frame certaintydegree does not easily increase, but the present disclosure is notlimited thereto. That is, for example, in the process of determiningwhether or not the above-described four conditions (C1 to C4) aresatisfied, when the line La is cut, and when the travel direction of thevehicle V is the advancing direction, the process is continued using aline of about 4 m obtained by extending a virtual line of about 2 m fromthe cut line. On the other hand, when the travel direction of thevehicle V is the retreating direction, the process is continued using aline of about 5 m obtained by extending a virtual line of about 3 m fromthe cut line. Thus, when the travel direction of the vehicle V is theadvancing direction, the level of the parking frame certainty degree maynot easily increase, as compared with a case where the travel directionof the vehicle V is the retreating direction.(3) In the present embodiment, the travel direction of the vehicle V isdetected using the above-described shift position sensor 20 and shiftposition calculation unit 10E, but the present disclosure is not limitedthereto. That is, for example, a longitudinal acceleration sensor thatdetects acceleration in the longitudinal direction of the vehicle body(vehicle longitudinal direction) may be provided in the vehicle V, andthe travel direction of the vehicle V may be detected based on theacceleration detected by the longitudinal acceleration sensor.(4) In the present embodiment, the acceleration suppression controlstart timing and the acceleration suppression control amount arecalculated based on the total certainty degree calculated by the totalcertainty degree calculation unit 40, but the present disclosure is notlimited thereto. That is, the acceleration suppression control starttiming and the acceleration suppression control amount may be calculatedbased on the parking frame entering certainty degree calculated by theparking frame entering certainty degree calculation unit 38 and thedetermination result of whether or not the travel direction of thevehicle V is the advancing direction or the retreating direction. Inthis case, the acceleration suppression control start timing and theacceleration suppression control amount are calculated by making theparking frame entering certainty degree suitable for an accelerationsuppression condition calculation map illustrated in FIG. 23, forexample. FIG. 23 is a diagram illustrating a modification example of thepresent embodiment.(5) In the present embodiment, when the vehicle V travels forward, theacceleration suppression degree of the vehicle V is made lower than thecase where the vehicle V travels rearward. However, the control of theacceleration degree is not limited to this. In other words, when thevehicle V travels rearward, the acceleration suppression degree of thevehicle V is made lower than the case where the vehicle V travelsforward.

Third Embodiment

Hereinafter, a third embodiment of the disclosure (hereinafter, referredto as “the present embodiment”) will be described with reference to theaccompanying drawings.

(Configuration)

First, a configuration of a vehicle acceleration suppression device 1 ofthe present embodiment will be described with reference to FIG. 24,while referring to FIG. 1 to FIG. 23. Since the vehicle accelerationsuppression device 1 of the present embodiment is the same as theabove-described first embodiment except for a process performed by theacceleration suppression control content calculation unit 10I,repetitive description may be omitted with respect to processes otherthan the process performed by the acceleration suppression controlcontent calculation unit 10I.

Further, the vehicle acceleration suppression device 1 of the presentembodiment is the same as the above-described first embodiment exceptfor processes performed by the parking frame certainty degreecalculation unit 36, the parking frame entering certainty degreecalculation unit 38, the total certainty degree calculation unit 40 inthe process performed by the acceleration suppression control contentcalculation unit 10I, and thus, repetitive description may be omitted.

In the above-described process of step S208, the parking frame certaintydegree calculation unit 36 of the present embodiment first receives aninput of a steering angle signal, determines whether or not the travelstate of the vehicle V is a turning state, and sets a setting movingdistance according to the determination result. Further, the parkingframe certainty degree calculation unit 36 performs a process ofdetermining whether or not the process of step S206 is continuouslychecked until the moving distance of the vehicle V reaches the settingmoving distance after the process of step S206 is started, based on thesetting moving distance set according to whether or not the travel stateof the vehicle V is the turning state.

Here, as the process of determining whether or not the travel state ofthe vehicle V is the turning state, for example, an operation amount(rotation angle) from the neutral position of the steering wheel 28included in the steering angle signal is referenced. Further, it isdetermined whether or not the referenced rotation angle exceeds a presetturning state determination threshold value (for example, 90°). Further,when the referenced rotation angle exceeds the turning statedetermination threshold value, it is determined that the vehicle V is inthe turning state.

The turning state determination threshold value is not limited to 90°,and for example, may be changed according to specification of thevehicle V, such as braking performance of the vehicle V. Further, forexample, the turning state determination threshold value may be changedaccording to a traffic law or the like of a place (nation or the like)where the vehicle V is traveling.

Here, the process of setting the setting moving distance according towhether or not the travel state of the vehicle V is the turning state isperformed with reference to the steering angle signal received from thesteering angle calculation unit 10C, for example.

Further, in the present embodiment, as an example, a case where thesetting moving distance is set to 2.5 m when it is determined that thetravel state of the vehicle V is not the turning state and is set to 1 mwhen it is determined that the travel state of the vehicle V is theturning state will be described.

The setting moving distance is exemplary, and for example, may bechanged according to specification of the vehicle V, such as brakingperformance of the vehicle V. Further, for example, the setting movingdistance may be changed according to a traffic law or the like of aplace (nation or the like) where the vehicle V is traveling.

Accordingly, in the present embodiment, in the process of step S208,when the travel state of the vehicle V is the turning state, the levelof the parking frame certainty degree is not easily calculated as “level1”, as compared with a case where the travel state of the vehicle V isnot the turning state.

Further, in the above-described process of step S314, the parking frameentering certainty degree calculation unit 38 of the present embodimentfirst determines whether or not the travel state of the vehicle V is theturning state.

When it is determined that the travel state of the vehicle V is not theturning state, a process of calculating the parking frame enteringcertainty degree as a low level in a non-turning state is performed. Onthe other hand, when it is determined that the travel state of thevehicle V is the turning state, a process of calculating the parkingframe entering certainty degree as a low level in the turning state isperformed.

In addition, in the above-described process of step S316, the parkingframe entering certainty degree calculation unit 38 first determineswhether or not the travel state of the vehicle V is the turning state.

When it is determined that the travel state of the vehicle V is not theturning state, a process of calculating the parking frame enteringcertainty degree as a high level in the non-turning state is performed.On the other hand, when it is determined that the travel state of thevehicle V is the turning state, a process of calculating the parkingframe entering certainty degree as a high level in the turning state isperformed.

Further, the total certainty degree calculation unit 40 of the presentembodiment performs the same process as that of the above-describedparking frame certainty degree calculation unit 36, for example, toperform a process of determining whether or not the travel state of thevehicle V is the turning state.

The total certainty degree calculation unit 40 of the present embodimentreceives an input of a parking frame certainty degree signal and aparking frame entering certainty degree signal, and makes a parkingframe certainty degree included in the parking frame certainty degreesignal and a parking frame entering certainty degree included in theparking frame entering certainty degree signal suitable for a totalcertainty degree calculation map illustrated in FIG. 24. Further, thetotal certainty degree calculation unit 40 calculates a total certaintydegree based on the parking frame certainty degree and the parking frameentering certainty degree.

FIG. 24 is a diagram illustrating the total certainty degree calculationmap used in the present embodiment. Further, in FIG. 24, similarly toFIG. 13, the parking frame certainty degree is represented as “framecertainty degree”, and the parking frame entering certainty degree isrepresented as “entering certainty degree”.

Here, the total certainty degree calculation map used by the totalcertainty degree calculation unit 40 of the present embodiment isdifferent from the total certainty degree calculation map used by thetotal certainty degree calculation unit 40 of the above-described firstembodiment, in which the level of the total certainty f degree actor ischanged according to the determination result of whether or not thevehicle V is in the turning state. In FIG. 24, the total certaintydegree when it is determined that the vehicle V is not in the turningstate is represented as “low level in non-turning state” and “high levelin non-turning state” in a unit of “entering certainty degree”. Inaddition, in FIG. 24, the total certainty degree when it is determinedthat the vehicle V is in the turning state is represented as “low levelin turning state” and “high level in turning state” in a unit of“entering certainty degree”.

The “low level in non-turning state” corresponds to the process ofcalculating the parking frame entering certainty degree as the low levelin the non-turning state in the above-described process of step S314.Further, the “low level in turning state” corresponds to the process ofcalculating the parking frame entering certainty degree as the low levelin the turning state in the above-described process of step S314.

Similarly, the “high level in non-turning state” corresponds to theprocess of calculating the parking frame entering certainty degree asthe high level in the non-turning state in the above-described processof step S316. Further, the “high level in turning state” corresponds tothe process of calculating the parking frame entering certainty degreeas the high level in the turning state in the above-described process ofstep S316.

Further, as illustrated in FIG. 24, the total certainty degreecalculation unit 40 of the present embodiment calculates the totalcertainty degree when it is determined that the vehicle V is in theturning state as a level which is equal to or higher than the totalcertainty degree when it is determined that the vehicle V is not in theturning state.

As an example of the process of calculating the total certainty degreeby the total certainty degree calculation unit 40 of the presentembodiment, when the parking frame certainty degree is “level 2” and theparking frame entering certainty degree is “high level in non-turningstate”, as illustrated in FIG. 24, the total certainty degree iscalculated as “low”. On the other hand, when the parking frame certaintydegree is “level 2” and the parking frame entering certainty degree is“high level in turning state”, as illustrated in FIG. 24, the totalcertainty degree is calculated as “high”.

Accordingly, in the present embodiment, when the vehicle V is in theturning state, the total certainty degree is easily calculated as ahigher level than a case where the vehicle V is not in the turningstate. Thus, in the present embodiment, when the vehicle V is in theturning state, the suppression degree of the acceleration instructionvalue increases, as compared with a case where the vehicle V is not inthe turning state.

(Operation)

Next, an example of the operation performed using the vehicleacceleration suppression device 1 of the present embodiment will bedescribed with reference to FIG. 1 to FIG. 24. With respect to the sameoperation or the like as that of the above-described first embodiment,repetitive description may be omitted.

In the example of the operation described below, similarly to theabove-described first embodiment, an example in which the vehicle V thattravels in a parking lot enters a parking frame L0 selected by a driverwill be described.

While the vehicle V is traveling, the parking frame certainty degreecalculation unit 36 calculates the parking frame certainty degree, andthe parking frame entering certainty degree calculation unit 38calculates the parking frame entering certainty degree. Further, thetotal certainty degree calculation unit 40 calculates the totalcertainty degree based on the parking frame certainty degree and theparking frame entering certainty degree.

Further, while the vehicle V is traveling, the acceleration suppressioncontrol start timing calculation unit 42 calculates the accelerationsuppression control start timing, and the acceleration suppressioncontrol amount calculation unit 44 calculates the accelerationsuppression control amount, based on the total certainty degreecalculated by the total certainty degree calculation unit 40.

Further, when it is determined that the vehicle V enters the parkingframe L0 and it is determined that the acceleration suppression controloperation condition is established, the acceleration suppressioninstruction value calculation unit 10J outputs the accelerationsuppression instruction value signal to the target throttle valveopening degree calculation unit 10K. Further, the target throttle valveopening degree calculation unit 10K outputs the target throttle valveopening degree signal to the engine controller 12.

Here, in the present embodiment, in the process of calculating the totalcertainty degree by the total certainty degree calculation unit 40, whenthe vehicle V is in the turning state, the total certainty degree iseasily calculated as a higher level than a case where the vehicle V isnot in the turning state.

Thus, in a state where the acceleration suppression control operationcondition is established, when the vehicle V is in the turning state,the suppression degree of the acceleration instruction value increasesas compared with a case where the vehicle V is not in the turning state.

The above-described steering angle sensor 18 and the steering anglecalculation unit 10C correspond to a vehicle turning state detector.Further, as described above, when the turning state of the vehicle V isnot detected, the vehicle acceleration suppression control method of thepresent embodiment is a method for suppressing the accelerationinstruction value depending on the operation amount of the acceleratorpedal 32 with a lower suppression degree than a case where the turningstate of the vehicle V is detected.

Effects of Third Embodiment

Hereinafter, effects of the present embodiment will be described. In thepresent embodiment, the following effects can be achieved, in additionto the effects of the above-described first embodiment.

(1) It is detected whether or not the vehicle V is in the turning stateby the steering angle sensor 18 and the steering angle calculation unit10C. In addition, when the vehicle V is not in the turning state, theacceleration suppression control start timing calculation unit 42, theacceleration suppression control amount calculation unit 44, theacceleration suppression instruction value calculation unit 10J, and thetarget throttle valve opening degree calculation unit 10K decrease thesuppression degree of the acceleration instruction value, as comparedwith a case where the vehicle V is in the turning state. That is, whenthe vehicle V is in the turning state, the acceleration suppressioncontrol start timing calculation unit 42, the acceleration suppressioncontrol amount calculation unit 44, the acceleration suppressioninstruction value calculation unit 10J, and the target throttle valveopening degree calculation unit 10K increase the suppression degree ofthe acceleration instruction value, as compared with a case where thevehicle V is not in the turning state. Thus, when the travel state ofthe vehicle V is the advancing state where the driver generally intendsacceleration, the suppression degree of the acceleration instructionvalue decreases as compared with a case where the travel state of thevehicle V is the turning state where the driver does not generallyintend acceleration as compared with the advancing state, to therebymake it possible to reduce deterioration of operability. Further, whenthe travel state of the vehicle V is the turning state where the driverdoes not generally intend acceleration as compared with the advancingstate, the suppression degree of the acceleration instruction valueincreases as compared with the advancing state where the drivergenerally intends acceleration, to thereby make it possible to enhancethe acceleration suppression effect of the vehicle V. As a result, it ispossible to suppress deterioration of operability of the vehicle V inparking the vehicle, and to suppress acceleration of the vehicle V dueto an operational error of the accelerator pedal 32.(2) In the vehicle acceleration suppression control method of thepresent embodiment, it is detected whether or not the vehicle V is inthe turning state, and when the turning state of the vehicle V is notdetected, the acceleration instruction value is suppressed with a lowersuppression degree than a case where the turning state of the vehicle Vis detected. Thus, when the travel state of the vehicle V is theadvancing state where the driver generally intends acceleration, thesuppression degree of the acceleration instruction value decreases ascompared with a case where the travel state of the vehicle V is theturning state where the driver does not generally intend acceleration ascompared with the advancing state, to thereby make it possible to reducedeterioration of operability. Further, when the travel state of thevehicle V is the turning state where the driver does not generallyintend acceleration as compared with the advancing state, thesuppression degree of the acceleration instruction value increases ascompared with the advancing state where the driver generally intendsacceleration, to thereby make it possible to enhance the accelerationsuppression effect of the vehicle V. Thus, it is possible to suppressdeterioration of operability of the vehicle V during parking, and tosuppress acceleration of the vehicle V due to an operational error ofthe accelerator pedal 32.

(Modifications)

(1) In the present embodiment, when the vehicle V is in the turningstate, the total certainty degree is easily calculated as a higher levelthan a case where the vehicle V is not in the turning state, so that thesuppression degree of the acceleration instruction value increases, butthe present disclosure is not limited thereto. That is, for example,when the vehicle V is in the turning state, by changing the accelerationsuppression control start timing or the acceleration suppression controlamount, the suppression degree of the acceleration instruction value mayincrease as compared with a case where the vehicle V is not in theturning state. Further, for example, when the vehicle V is in theturning state, the parking frame certainty degree or the parking frameentering certainty degree may be easily calculated as a higher levelthan a case where the vehicle V is not in the turning state, so that thesuppression degree of the acceleration instruction value may increase.(2) In the present embodiment, the turning state determination thresholdvalue is set to the value (for example 90°) corresponding to therotation angle of the steering wheel 28, but the turning statedetermination threshold value is not limited thereto. That is, thevehicle V may be configured to include a yaw rate sensor that detects ayaw rate of the vehicle V, and the turning state determination thresholdvalue may be set to a value (for example, 100 [R]) corresponding to theyaw rate of the vehicle V. Further, the vehicle V may be configured toinclude a turning angle sensor that detects a turning angle of a turningwheel (for example, right front wheel WFR and left front wheel WFL), andthe turning state determination threshold value may be set to a value(for example, 6°) corresponding to the turning angle of the turningwheel.(3) In the present embodiment, the acceleration suppression controlstart timing and the acceleration suppression control amount arecalculated based on the total certainty degree calculated by the totalcertainty degree calculation unit 40, but the present disclosure is notlimited thereto. That is, the acceleration suppression control starttiming and the acceleration suppression control amount may be calculatedbased on the parking frame entering certainty degree calculated by theparking frame entering certainty degree calculation unit 38 and thedetermination result of whether or not the vehicle V is in the turningstate. In this case, the acceleration suppression control start timingand the acceleration suppression control amount are calculated by makingthe parking frame entering certainty degree suitable for an accelerationsuppression condition calculation map illustrated in FIG. 25, forexample. FIG. 25 is a diagram illustrating a modification example of thepresent embodiment.

Further, in a state where the acceleration suppression conditioncalculation map illustrated in FIG. 25 is used, when the travel state ofthe vehicle V is the turning state, for example, the accelerationsuppression control start timing and the acceleration suppressioncontrol amount may be calculated using the acceleration suppressioncondition calculation map similarly to that illustrated in FIG. 22.

Further, the acceleration suppression control start timing and theacceleration suppression control amount may be calculated based on onlythe parking frame entering certainty degree calculated by the parkingframe entering certainty degree calculation unit 38. In this case, forexample, the acceleration suppression control start timing and theacceleration suppression control amount may be calculated using anacceleration suppression condition calculation map illustrated in FIG.26. FIG. 26 is a diagram illustrating a modification example of thepresent embodiment.

Fourth Embodiment

Hereinafter, a fourth embodiment of the disclosure (hereinafter,referred to as “the present embodiment”) will be described withreference to the accompanying drawings.

(Configuration)

First, a configuration of a vehicle acceleration suppression device 1 ofthe present embodiment will be described with reference to FIG. 27,while referring to FIG. 1 to FIG. 26. Since the vehicle accelerationsuppression device 1 of the present embodiment is the same as theabove-described first embodiment except for a process performed by theacceleration suppression control content calculation unit 10I,repetitive description may be omitted with respect to processes otherthan the process performed by the acceleration suppression controlcontent calculation unit 10I.

Further, the vehicle acceleration suppression device 1 of the presentembodiment is the same as the above-described first embodiment exceptfor processes performed by the acceleration suppression operationcondition determination unit 34 and the total certainty degreecalculation unit 40 in the process performed by the accelerationsuppression control content calculation unit 10I, and thus, repetitivedescription may be omitted.

In the above-described process of step S106, the accelerationsuppression operation condition determination unit 34 of the presentembodiment performs a process of determining which one of predeterminedplural vehicle speed threshold value ranges the vehicle speed of thevehicle V is suitable for. Further, after the process of step S106 isperformed, the process performed by the acceleration suppressionoperation condition determination unit 34 of the present embodimentprogresses to step S108.

In the present embodiment, as an example, as illustrated in FIG. 27, acase where four ranges are set as the plural vehicle speed thresholdvalue ranges will be described. Further, FIG. 27 illustrates a map usedin the process performed by the acceleration suppression control contentcalculation unit 10I of the present embodiment, in which therelationship between the vehicle speed and the control content isillustrated.

Here, the four vehicle speed threshold value ranges include a firstvehicle speed range of 0 km/h, a second vehicle speed range of 0 km/h orgreater and 15 km/h or less, a third vehicle speed range of greater than15 km/h and 20 km/h or less, and a fourth vehicle speed range of greaterthan 20 km/h.

Next, in the above-described process of step S118, the accelerationsuppression operation condition determination unit 34 of the presentembodiment changes the condition for determining that the vehicle Venters the parking frame based on the vehicle speed threshold valuerange for which the vehicle speed of the vehicle V is suitable,determined in step S106. In FIG. 27, the condition for determining thatthe vehicle V enters the parking frame, which serves as a condition fordetermining whether or not the acceleration suppression control isstarted, is represented as “control start” in a unit of “controlcontent”.

As a specific example of the process of changing the condition fordetermining that the vehicle V enters the parking frame, when thevehicle speed of the vehicle V is in the first vehicle speed range orthe second vehicle speed range, a process of setting the above-describedsetting value of the condition A as the same value as in theabove-described first embodiment is described. Here, the setting valueof the condition A includes at least one of the above-described settingsteering value, setting time, setting angle, and setting distance. InFIG. 27, a state where the setting value of the condition (A1 to A3) isset as the same value as in the first embodiment is represented as sign“O”.

On the other hand, when the vehicle speed of the vehicle V is in thethird vehicle speed range or the fourth vehicle speed range, the settingvalue of the condition A is changed to a value in which it is not easilydetermined that the vehicle V enters the parking frame, as compared withthe first embodiment. This is performed by a process of changing thesetting time in the condition A1 to a longer time than the firstembodiment, for example. In FIG. 27, a state where the setting value ofthe condition A is changed to the value in which it is not easilydetermined that the vehicle V enters the parking frame as compared withthe first embodiment is represented as “regulation of control startcondition”.

Further, in a state where the acceleration suppression control isoperated, the acceleration suppression operation condition determinationunit 34 of the present embodiment changes a condition for continuing theacceleration suppression control during operation based on the vehiclespeed threshold value range for which the vehicle speed of the vehicle Vis suitable, determined in step S106. In FIG. 27, the condition forcontinuing the acceleration suppression control during operation isrepresented as “control continuation” in a unit of “control content”.

As a specific example of the process of changing the condition forcontinuing the acceleration suppression control during operation, whenthe vehicle speed of the vehicle V corresponds to a vehicle speed otherthan the fourth vehicle speed range, the process of continuing theacceleration suppression control during operation is performed. In FIG.27, a state where the acceleration suppression control during operationis continued is represented as sign “O”.

On the other hand, when the vehicle speed of the vehicle V is in thefourth vehicle speed range, for example, a process of changing thesetting value of the condition A to the value in which it is not easilydetermined that the vehicle V enters the parking frame to easilyterminate the acceleration suppression control during operation isperformed, as compared with the first embodiment. In FIG. 27, a statewhere the acceleration suppression control during operation is easilyterminated is represented as “alleviation of control terminationcondition”.

Further, the total certainty degree calculation unit 40 of the presentembodiment performs a process of determining which vehicle speedthreshold value range the vehicle speed of the vehicle V is suitablefor, similarly to the process performed by the acceleration suppressionoperation condition determination unit 34 by receiving the input of thevehicle speed calculation value signal. In the process of determiningwhich vehicle speed threshold value range the vehicle speed of thevehicle V is suitable for, performed by the total certainty degreecalculation unit 40, the processing result performed by the accelerationsuppression operation condition determination unit 34 may be used.

Further, the total certainty degree calculation unit 40 of the presentembodiment performs a process of calculating the total certainty degreebased on the parking frame certainty degree and the parking frameentering certainty degree, and performs a process of changing the levelof the total certainty degree based on the vehicle speed threshold valuerange for which the vehicle speed of the vehicle V is suitable. In FIG.27, the process of changing the level of the total certainty degree isrepresented as “certainty degree” in a unit of “control content”.

As a specific example of the process of changing the level of the totalcertainty degree, when the vehicle speed of the vehicle V is in thefirst vehicle speed range or the second vehicle speed range, a processof maintaining the level of the total certainty degree calculated basedon the parking frame certainty degree and the parking frame enteringcertainty degree is performed. In FIG. 27, a state where the level ofthe total certainty degree calculated based on the parking framecertainty degree and the parking frame entering certainty degree ismaintained is represented as sign “−”.

On the other hand, when the vehicle speed of the vehicle V is in thethird vehicle speed range, if the acceleration suppression control isbeing operated, a process of maintaining the level of the totalcertainty degree calculated based on the parking frame certainty degreeand the parking frame entering certainty degree is performed. In FIG.27, a state where the level of the total certainty degree while theacceleration suppression control is being operated is maintained isrepresented as “maintain certainty degree during control”.

Further, when the vehicle speed of the vehicle V is the third vehiclespeed range, if the acceleration suppression control is not operated, aprocess of decreasing (for example, by one step) the level of the totalcertainty degree calculated based on the parking frame certainty degreeand the parking frame entering certainty degree is performed. In FIG.27, a state where the level of the total certainty degree is decreasedin a state where the acceleration suppression control is not operated isrepresented as “decrease of certainty degree level during non-control”.

Further, when the vehicle speed of the vehicle V is in the fourthvehicle speed range, a process of decreasing (for example, by one step)the level of the total certainty degree calculated based on the parkingframe certainty degree and the parking frame entering certainty degreeis performed, regardless of whether or not the acceleration suppressioncontrol is operated. In FIG. 27, a state where the level of the totalcertainty degree is decreased regardless of whether or not theacceleration suppression control is operated is represented as “uniformdecrease of certainty degree level”.

Accordingly, in the present embodiment, as the vehicle speed of thevehicle V is high, the total certainty degree is easily calculated as alow level. Thus, in the present embodiment, as the vehicle speed of thevehicle V is low, the acceleration instruction value is suppressed witha high suppression degree.

(Operation)

Next, an example of the operation performed using the vehicleacceleration suppression device 1 of the present embodiment will bedescribed with reference to FIG. 1 to FIG. 27. With respect to the sameoperation or the like as that of the above-described first embodiment,repetitive description may be omitted. In the example of the operationdescribed below, similarly to the above-described first embodiment, anexample in which the vehicle V that travels in a parking lot enters aparking frame L0 selected by a driver will be described.

While the vehicle V is traveling, the parking frame certainty degreecalculation unit 36 calculates the parking frame certainty degree, andthe parking frame entering certainty degree calculation unit 38calculates the parking frame entering certainty degree. Further, thetotal certainty degree calculation unit 40 calculates the totalcertainty degree based on the parking frame certainty degree and theparking frame entering certainty degree.

Further, while the vehicle V is traveling, the acceleration suppressioncontrol start timing calculation unit 42 calculates the accelerationsuppression control start timing, and the acceleration suppressioncontrol amount calculation unit 44 calculates the accelerationsuppression control amount, based on the total certainty degreecalculated by the total certainty degree calculation unit 40.

Further, when it is determined that the vehicle V enters the parkingframe L0 and it is determined that the acceleration suppression controloperation condition is established, the acceleration suppressioninstruction value calculation unit 10J outputs the accelerationsuppression instruction signal to the target throttle valve openingdegree calculation unit 10K. Further, the target throttle valve openingdegree calculation unit 10K outputs the target throttle valve openingdegree signal to the engine controller 12.

Here, in the present embodiment, in the process of calculating the totalcertainty degree by the total certainty degree calculation unit 40, asthe vehicle speed of the vehicle V is high, the total certainty degreeis easily calculated as a low level. Thus, in a state where theacceleration suppression control operation condition is established, asthe vehicle speed of the vehicle V is lower, the accelerationinstruction value is suppressed with a higher suppression degree.

The above-described vehicle wheel speed sensor 16 and vehicle speedcalculation unit 10B correspond to a vehicle speed detector. Further, asdescribed above, as the vehicle speed of the vehicle V is higher, thevehicle acceleration suppression control method of the presentembodiment is a method for suppressing the acceleration instructionvalue depending on the operation amount of the accelerator pedal 32 witha lower suppression degree.

Effects of Fourth Embodiment

Hereinafter, effects of the present embodiment will be described. In thepresent embodiment, the following effects can be achieved, in additionto the effects of the above-described first embodiment.

(1) The vehicle speed of the vehicle V is detected by the vehicle wheelspeed sensor 16 and the vehicle speed calculation unit 10B. In addition,as the vehicle speed of the vehicle V is higher, the accelerationsuppression control start timing calculation unit 42, the accelerationsuppression control amount calculation unit 44, the accelerationsuppression instruction value calculation unit 10J, and the targetthrottle valve opening degree calculation unit 10K suppress theacceleration instruction value with a lower suppression degree. That is,as the vehicle speed of the vehicle V is lower, the accelerationsuppression control start timing calculation unit 42, the accelerationsuppression control amount calculation unit 44, the accelerationsuppression instruction value calculation unit 10J, and the targetthrottle valve opening degree calculation unit 10K suppress theacceleration instruction value with a higher suppression degree. Thus,when the vehicle speed of the vehicle V is high and there is a highpossibility that the driver does not intend parking of the vehicle V,the suppression degree of the acceleration instruction value decreasesas compared with a case where the vehicle speed of the vehicle V is lowand there is a high possibility that the driver intends parking of thevehicle V. Thus, it is possible to reduce deterioration of operability.Further, when the vehicle speed of the vehicle V is low and there is ahigh possibility that the driver intends parking of the vehicle V, thesuppression degree of the acceleration instruction value increases ascompared with a case where the vehicle speed of the vehicle V is highand there is a high possibility that the driver intends parking of thevehicle V. Thus, it is possible to enhance the acceleration suppressioneffect of the vehicle V. As a result, it is possible to suppressdeterioration of operability of the vehicle V in parking the vehicle,and to restrict acceleration of the vehicle V due to an operationalerror of the accelerator pedal 32.(2) In the vehicle acceleration suppression control method of thepresent embodiment, as the vehicle speed of the vehicle V is higher, theacceleration instruction value is suppressed with a lower suppressiondegree. Thus, when the vehicle speed of the vehicle V is high and thereis a high possibility that the driver does not intend parking of thevehicle V, the suppression degree of the acceleration instruction valuedecreases as compared with a case where the vehicle speed of the vehicleV is low and there is a high possibility that the driver intends parkingof the vehicle V. Thus, it is possible to reduce deterioration ofoperability. Further, when the vehicle speed of the vehicle V is low andthere is a high possibility that the driver intends parking of thevehicle V, the suppression degree of the acceleration instruction valueincreases as compared with a case where the vehicle speed of the vehicleV is high and there is a high possibility that the driver does notintend parking of the vehicle V. Thus, it is possible to enhance theacceleration suppression effect of the vehicle V. As a result, it ispossible to suppress deterioration of operability of the vehicle V inparking the vehicle, and to suppress acceleration of the vehicle V dueto an operational error of the accelerator pedal 32.

(Modifications)

(1) In the present embodiment, as the vehicle speed of the vehicle V ishigher, the total certainty degree is easily calculated as a lowerlevel, so that the suppression degree of the acceleration instructionvalue decreases, but the present disclosure is not limited thereto. Thatis, for example, the acceleration suppression control start timing orthe acceleration suppression control amount may be changed, so that asthe vehicle speed of the vehicle V is higher, the suppression degree ofthe acceleration instruction value may decrease. Further, for example,as the vehicle speed of the vehicle V is higher, the parking framecertainty degree or the parking frame entering certainty degree may beeasily calculated as a lower level, so that the suppression degree ofthe acceleration instruction value may decrease.(2) In the present embodiment, four ranges are set as the plural vehiclespeed threshold value ranges, but the present disclosure is not limitedthereto. As the plural vehicle speed threshold value ranges, two ranges,three ranges, or five or more ranges may be set. Further, the settingspeed of each vehicle speed threshold value range is not limited to theabove-described speed, and for example, may be changed and set accordingto specification of the vehicle V such as braking performance of thevehicle V.

Hereinbefore, the description has been made with reference to a limitednumber of embodiments, but the scope of the present disclosure is notlimited thereto, and includes modifications of each embodiment based onthe disclosure which are obvious to those skilled in the art.

The invention claimed is:
 1. A vehicle acceleration suppression devicethat suppresses acceleration of a vehicle depending on an operationamount of a driving force instruction element that instructs a drivingforce by operation of a driver to perform a suppression control of thedriving force, the vehicle acceleration suppression device comprising:an accelerator operation detection sensor configured to detect anopening degree of an accelerator pedal; an acceleration controllerconfigured to control acceleration of the vehicle depending on theopening degree detected by the accelerator operation detection sensor; aperipheral environment recognizer configured to recognize a peripheralenvironment of the vehicle based on detection information of aperipheral environment recognition sensor provided in the vehicle; avehicle travel state detector configured to detect a travel state of thevehicle; a vehicle travel direction detector configured to detect atravel direction of the vehicle; a parking frame entering certaintydegree calculation unit configured to set a parking frame enteringcertainty degree indicating a degree of certainty that the vehicleenters a parking frame based on the environment recognized by theperipheral environment recognizer and the travel state detected by thevehicle travel state detector; and an acceleration suppression unitconfigured to suppress the acceleration controlled by the accelerationcontroller based on the parking frame entering certainty degree set bythe parking frame entering certainty degree calculation unit and thetravel direction detected by the travel direction detector, wherein whenthe travel direction detected by the vehicle travel direction detectoris forward, the acceleration suppression unit is configured to set asuppression degree of the acceleration of the vehicle to be lower thanwhen the travel direction detected by the vehicle travel directiondetector is backward.
 2. The vehicle acceleration suppression deviceaccording to claim 1, wherein the acceleration suppression unit delaysan acceleration suppression control start timing which is a timing whenthe suppression of the acceleration controlled by the accelerationcontroller starts to decrease the suppression degree of theacceleration.
 3. The vehicle acceleration suppression device accordingto claim 2, wherein the acceleration suppression unit decreases anacceleration suppression control amount which is a control amount forsuppressing the acceleration controlled by the acceleration controllerto decrease the suppression degree of the acceleration.
 4. The vehicleacceleration suppression device according to claim 1, wherein theacceleration suppression unit decreases an acceleration suppressioncontrol amount which is a control amount for suppressing theacceleration controlled by the acceleration controller to decrease thesuppression degree of the acceleration.
 5. A vehicle accelerationsuppression method for suppressing acceleration of a vehicle dependingon an operation amount of a driving force instruction element thatinstructs a driving force by operation of a driver to perform asuppression control of the driving force, the vehicle accelerationsuppression method comprising: detecting an opening degree of anaccelerator pedal, a travel state of the vehicle, and a travel directionof the vehicle; recognizing a peripheral environment of the vehicle;setting a parking frame entering certainty degree indicating a degree ofcertainty that the vehicle enters a parking frame based on therecognized environment and the detected travel state; and when thetravel direction detected by the detecting step is forward, setting asuppression degree of the acceleration of the vehicle to be lower thanwhen the travel direction detected by the detecting step is backward. 6.A vehicle acceleration suppression device comprising: an acceleratoroperation detection sensor configured to detect an opening degree of anaccelerator pedal to be operated by a driver of a vehicle to instruct adriving force; a travel controller configured to control acceleration ofthe vehicle depending on the opening degree of the accelerator pedaldetected by the accelerator operation detection sensor; a peripheralenvironment recognition sensor configured to capture a peripheral imageof the vehicle; a vehicle wheel speed sensor configured to detect arotational speed of a wheel of the vehicle; and a shift position sensorconfigured to detect a shift position of the vehicle; wherein the travelcontroller is configured to set a parking frame entering certaintydegree indicating a degree of certainty that the vehicle enters aparking frame based on the peripheral image captured by the peripheralenvironment recognition sensor and the rotational speed of the wheeldetected by the vehicle wheel speed sensor, wherein the travelcontroller is configured to suppress the acceleration of the vehiclebased on the parking frame entering certainty degree and the a traveldirection of the vehicle to be recognized by the shift position of thevehicle detected by the shift position sensor, and wherein when thetravel direction is forward, the travel controller is configured to seta suppression degree of the acceleration of the vehicle to be lower thanwhen the travel direction is backward.